Setembro 22, 2014

Orthogonal quotes

"What happens, happens," Carla offered gnomically. "Everything in the Cosmos has to be consistent. All we get to do is talk about it in a way that makes sense to us"


[...] imagine the time when wave mechanics powers every machine and everyone takes it for granted. Do you really want them thinking that it fell from the sky, fully formed, when the truth is that they owe their good fortune to the most powerful engine of change in the history: people arguing about science.


The cosmos is what it is. The laws of optics and mechanics and gravity are simple and elegant and universal... but a detailed description of all the things on which those laws play out seems to be nothing but a set of brute facts that need to be discovered individually. I mean, a 'typical' cosmos, in statistical terms, would be a gas in thermal equilibrium filling the void, with no solid objects at all. There certainly wouldn't be steep entropy gradients. We've only be treating the existence of such gradient as a 'law' because it was the most prominent fact in our lives: time came with a arrow distinguishing the past from the future.

Greg Egan, Orthogonal (books II & III)

Setembro 01, 2014

Primitive man, aware of his helplessness against the forces of Nature but totally ignorant of their causes, would try to compensate for his ignorance by inventing hypotheses about them [...]  For one who has no comprehension of physical law, but is aware of his own consciousness and volition, the natural question to ask is not: "What is causing it?", but rather: "Who is causing it?"  [...] The error [Mind Projection Fallacy] occurs in two complementary forms, which we might indicate thus: (a) My own imagination => Real Property of Nature, and (b) My own ignorance => Nature is indeterminate.

The philosophical dierence between conventional probability theory and probability theory as logic is that the former allows only sampling distributions, interprets them as physically real frequencies of "random variables", and rejects the notion of probability of an hypothesis as being meaningless. We take just the opposite position: that the probability of an hypothesis is the fundamental, necessary ingredient in all inference, and the notion of "randomness" is a red herring, at best irrelevant. [...] by "probability theory as logic" we mean nothing more than applying the standard product and sum rules of probability theory to whatever propositions are of interest in our problem.

We do not seek to explain "statistical behavior" because there is no such thing; what we see in Nature is physical behavior, which does not conflict in any way with deterministic physical law.

[...] as in any other problem of inference, we never ask, "Which quantities are random?" The relevant question is: "Which quantities are known, and which are unknown?"

Agosto 24, 2014

"He never sees [Thomas] More – a star in another firmament, who acknowledges him with a grim nod – without wanting to ask him, what's wrong with you? Or what's wrong with me? Why does everything you know, and everything you've learned, confirm you in what you believed before? Whereas in my case, what I grew up with, and what I thought I believed, is chipped away a little and a little, a fragment then a piece and then a piece more. With every month that passes, the corners are knocked off the certainties of this world: and the next world too. Show me where it says, in the Bible, ‘Purgatory’. Show me where it says relics, monks, nuns. Show me where it says ‘Pope’." 

"[...] it is no use to justify yourself. It is no good to explain. It is weak to be anecdotal. It is wise to conceal the past even if there is nothing to conceal. A man's power is in the half-light, in the half-seen movements of his hand and the unguessed-at expression of his face. It is the absence of facts that frightens people: the gap you open, into which they pour their fears, fantasies, desires."

Wolf Hall, Hilary Mantel

Maio 25, 2014

In the eye of the beholder

"Neither good nor ill is done to us by Fortune: she merely offers us the matter and the seeds: our soul, more powerful than she is, can mould it or sow them as she pleases, being the only cause and mistress of our happy state or our unhappiness. Whatever comes to us from outside takes its savour and its colour from our internal attributes, just as our garments warm us not with their heat but ours, which they serve to preserve and sustain. Shelter a cold body under them and it will draw similar services from them for its coldness: that is how we conserve snow and ice. Study to the lazy, like abstinence from wine to the drunkard, is torture; frugal living to the seeker after pleasure, like exercise to the languid idle man, is torment: so too for everything else. Things are not all that painful nor harsh in themselves: it is our weakness, our slackness, which makes them so. To judge great and lofty things we need a mind which is like them: otherwise we attribute to them the viciousness which belongs to ourselves. A straight oar seems bent in water. It is not only seeing which counts: how we see counts too." Essay XIV, "That the taste of good and evil things depends in large part on the opinion we have of them", Michel de Montaigne

Maio 21, 2014


Maio 18, 2014


"In plain truth, lying is an accursed vice. We are not men, nor have other tie upon one another, but by our word. If we did but discover the horror and gravity of it, we should pursue it with fire and sword, and more justly than other crimes. I see that parents commonly, and with indiscretion enough, correct their children for little innocent faults, and torment them for wanton tricks, that have neither impression nor consequence; whereas, in my opinion, lying only, and, which is of something a lower form, obstinacy, are the faults which are to be severely whipped out of them, both in their infancy and in their progress, otherwise they grow up and increase with them; and after a tongue has once got the knack of lying, 'tis not to be imagined how impossible it is to reclaim it whence it comes to pass that we see some, who are otherwise very honest men, so subject and enslaved to this vice. I have an honest lad to my tailor, whom I never knew guilty of one truth, no, not when it had been to his advantage. If falsehood had, like truth, but one face only, we should be upon better terms; for we should then take for certain the contrary to what the liar says: but the reverse of truth has a hundred thousand forms, and a field indefinite, without bound or limit. The Pythagoreans make good to be certain and finite, and evil, infinite and uncertain. There are a thousand ways to miss the white, there is only one to hit it." -- Essays IX, "Of Liars", Michel de Montaigne

Janeiro 31, 2014

Unwelt II

"In 1909, the biologist Jakob von Uexküll introduced the concept of the umwelt. He wanted a word to express a simple (but often overlooked) observation: different animals in the same ecosystem pick up on different environmental signals. In the blind and deaf world of the tick, the important signals are temperature and the odor of butyric acid. For the black ghost knifefish, it's electrical fields. For the echolocating bat, it's air-compression waves. The small subset of the world that an animal is able to detect is its umwelt. The bigger reality, whatever that might mean, is called the umgebung. The interesting part is that each organism presumably assumes its umwelt to be the entire objective reality "out there." Why would any of us stop to think that there is more beyond what we can sense?" David M. Eagleman

Janeiro 17, 2014

A impossibilidade do realismo

"What we would all like [...] is an understanding of the fundamental processes that govern the Universe, an understanding that is not just useful for calculation but an understanding that is true in some deeper sense. Typically, a scientist sees the latter point as either obvious and important, or else completely irrelevant. I would like to argue that we don’t have a choice; there is some very clear sense in which truth is not what is returned by any finite scientific investigation; all that is returned is plausibilities (some of which become very very high), and those plausibilities relate not directly to the truth of the hypotheses in question, but rather to their use or value in describing the data. 

The fundamental reason scientific investigations can’t obtain literal truth is that no scientific investigator ever has an exhaustive (and mutually exclusive) set of hypotheses. Plausibility calculations are calculations of measure in some space, which for our purposes we can take to be the space formed by the union of every possible set of scientific hypotheses, with their parameters and adjustments set to every possible set of values." -- David Hogg, Is cosmology just a plausibility argument?.

Janeiro 15, 2014


[...] reductionism is not so much a positive hypothesis, as the absence of belief—in particular, disbelief in a form of the Mind Projection Fallacy. [...] we use entirely different models to understand the aerodynamics of a 747 and a collision between gold nuclei in the Relativistic Heavy Ion Collider.  A computer modeling the aerodynamics of a 747 may not contain a single token, a single bit of RAM, that represents a quark. So is the 747 made of something other than quarks?  No, you're just modeling it with representational elements that do not have a one-to-one correspondence with the quarks of the 747.  The map is not the territory. [...] As the saying goes, "The map is not the territory, but you can't fold up the territory and put it in your glove compartment."  Sometimes you need a smaller map to fit in a more cramped glove compartment—but this does not change the territory.  The scale of a map is not a fact about the territory, it's a fact about the map.


To build a fully accurate model of the 747, it is not necessary, in principle, for the model to contain explicit descriptions of things like airflow and lift.  There does not have to be a single token, a single bit of RAM, that corresponds to the position of the wings.  It is possible, in principle, to build an accurate model of the 747 that makes no mention of anything except elementary particle fields and fundamental forces.
"What?" cries the antireductionist.  "Are you telling me the 747 doesn't really have wings?  I can see the wings right there!"
The notion here is a subtle one.  It's not just the notion that an object can have different descriptions at different levels.
It's the notion that "having different descriptions at different levels" is itself something you say that belongs in the realm of Talking About Maps, not the realm of Talking About Territory.

It's not that the airplane itself, the laws of physics themselves, use different descriptions at different levels—as yonder artillery gunner thought.  Rather we, for our convenience, use different simplified models at different levels.


So when your mind simultaneously believes explicit descriptions of many different levels, and believes explicit rules for transiting between levels, as part of an efficient combined model, it feels like you are seeing a system that is made of different level descriptions and their rules for interaction.

But this is just the brain trying to be efficiently compress an object that it cannot remotely begin to model on a fundamental level.  The airplane is too large.  Even a hydrogen atom would be too large.  Quark-to-quark interactions are insanely intractable.  You can't handle the truth.

But the way physics really works, as far as we can tell, is that there is only the most basic level—the elementary particle fields and fundamental forces.  You can't handle the raw truth, but reality can handle it without the slightest simplification.  (I wish I knew where Reality got its computing power.)

The laws of physics do not contain distinct additional causal entities that correspond to lift or airplane wings, the way that the mind of an engineer contains distinct additional cognitive entities that correspond to lift or airplane wings.

This, as I see it, is the thesis of reductionism.  Reductionism is not a positive belief, but rather, a disbelief that the higher levels of simplified multilevel models are out there in the territory.  Understanding this on a gut level dissolves the question of "How can you say the airplane doesn't really have wings, when I can see the wings right there?"  The critical words are really and see." -- Yudkowsky (

DanielLC reply to another comment: "One minor quibble; how do we know there is any most basic level?". Levels are an attribute of the map. The territory only has one level. Its only level is the most basic one. Let's consider a fractal. The Mandelbrot set can be made by taking the union of infinitely many iterations. You could think of each additional iteration as a better map. That being said, either a point is in the Mandelbrot set or it is not. The set itself only has one level.

Dezembro 14, 2013

Farewell to Reality

"[...] reality is a metaphysical concept — it lies beyond the grasp of science. When we adopt specific beliefs about reality, what we are actually doing is adopting a specific philosophical position

There is no quantum world. There is only an abstract quantum physical description. It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature.

This ‘working model’ of science acknowledges that reality-in-itself is metaphysical, that the objects of scientific study are the shadows, the things-as-they-appear or things-as-they-are-measured. It accepts that the facts that scientists work with are not theory-neutral — they do not come completely free from contamination by theoretical concepts. It accepts that theories are in their turn populated by metaphysical concepts and mathematical abstractions and are derived by any method that works, from induction to the most extreme speculation. It acknowledges that theories can never be accepted as the ultimate truth. Instead, they are accepted as possessing a high truth-likeness or verisimilitude — they correspond to the facts. In this way they become part of the authorized version of empirical reality. Finally, the model acknowledges the important role played by the Copernican attitude. Science works best when we resist the temptation to see ourselves as the primary objective or purpose of reality" -- Jim Baggott, Farewell to Reality

Outubro 23, 2013


"O que acontece quando queremos ter alguém num contrato de associação mas depois não conseguimos ter ninguém  a tempo inteiro?

A P. é uma mulher 30 anos, bancária, vive sozinha, faz o que gosta. Tem  uma história familiar que a faz desconfiar do purgatório das  boas intenções:  andou de um lado para o outro, entre pais e avós ( problemas de migrações, distâncias, chegadas). Passada a fase dos amores em prato do dia, sente agora a falta de um respaldo. Pois, mas P. tem uma pedra no sapato: como confiar?
A pergunta dela é uma boa pergunta como dizia o Jim Hacker do  Yes , Minister, porque é uma pergunta que todos fazem, mas atira ao lado. P. somatizou a ansiedade destes anos e, por coincidência, foi a pele, a última fronteira, que pagou. Para sobremesa, desenvolveu um jogo de damas com o evitamento fóbico: só está onde pode estar. A ilusão do controlo também tem direito à vida.
O desejo é a distância tornada sensível, registou  um senhor  (Blanchot) com que incomodo sempre os meus leitores de blogues. Uma das interpretações : o desejo é o que te torna indefeso, é o que anula a  distância. A P. tem olhado para  a confiança como condição prévia e por  isso todas as distâncias lhe parecem estradas de salteadores." -- Filipe Nunes Vicente 

Eu sou ainda mais literal na frase de Blanchot. Somos, temos, distância para quase tudo mas nem tudo é motivo de atenção, de posse (enfim, de desejo). Aquilo que queremos, o que assim passa a alvo, começa a ecoar no nosso mundo interno. A distância que sempre lá esteve torna-se visível. Mais um dos muitos faróis que nos guia os erros.

Agosto 05, 2013

Philosophy in The Flesh II

the mind is embodied, not in any trivial sense (e.g., the "wetware" of the brain runs the software of the mind), but in the deep sense that our conceptual systems and our capacity for thought are shaped by the nature of our brains, our bodies, and our bodily interactions. There is no mind separate from and independent of the body, nor are there thoughts that have an existence independent of bodies and brains. (pg.265)

the assertion that empirical knowledge of our moral cognition can have no normative implications, is based on a false dichotomy between facts and values. Owen Flanagan (Cl, 1991) has demonstrated the relevance of moral psychology for moral theory by showing that no morality can be adequate if it is inconsistent with what we know about moral development, emotions, gender differences, and self-identity. Johnson (Cl, 1993) argues that facts about human conceptualization and reasoning place normative constraints on what we can morally demand of ourselves and others. For example, any view of morality that involves absolute moral principles defined by literal concepts cannot be cognitively realistic for human beings, whose moral categories often involve radial structure, conceptual metaphor, and metonymy. Damasio's (B1, 1994) work with brain damaged patients who have lost the ability to perform certain kinds of practical reasoning because their emotional experience is impaired suggests that moral deliberation cannot be the product of an allegedly pure reason. Moral deliberation always requires emotional monitoring and an interplay of affect and reason. (pg.326)

Philosophical theories, like all theories, do not and cannot spring full-blown from some alleged pure, transcendent reason. Instead, philosophy is built up with the conceptual and inferential resources of a culture, even though it may transform and creatively extend those resources. These cognitive resources are not arbitrary or merely culturally constructed. They depend on the nature of our embodied experience, which includes both the constraints set by our bodily makeup and those imposed by the environments we inhabit. (pg.341)

It is natural to ask questions about the nature of things. As Aristotle said at the beginning of the Metaphysics, "All men by nature desire to know." We desire to know, for practical reasons, if the mushroom we are about to eat is poisonous. We desire to know, for ethical reasons, if there is some natural difference between men and women. We desire to know, for purely intellectual reasons, whether the universe will come to an end someday. 

The very project of seeking knowledge assumes that the world makes systematic sense, that it is not just a random collection of individual phenomena. It is not just determined by the capricious whims of gods who are fickle, mischievous, and cruel, but, rather, it is a "cosmos," a rationally structured whole. In other words, to seek knowledge, we must assume that the world is not absurd. It also assumes that we can gain knowledge of the world. 

These two assumptions together define what has come down to us as a commonplace folk theory that we take for granted any time we seek any kind of systematic knowledge:

The world makes systematic sense, and we can gain knowledge of it.

Thus it is natural for us to ask what things are like and why they behave the way they do. Moreover, we seek general knowledge, knowledge about kinds of things, not just particular knowledge that pertains only to a single entity. We want to know whether this mushroom is edible, but our knowledge of it depends on our knowledge of the general kind of mushroom it is. We want to know whether men and women are somehow fundamentally different and not just whether this man differs in certain particular ways from this woman. And we assume that such questions have answers, that if we can formulate such a question, there is a fact of the matter that answers it. In other words, much of the time we assume two particular folk theories about things in general:

Every particular thing is a kind of thing.

Every entity has an "essence" or "nature," that is, a collection of properties that makes it the kind of thing it is and that is the causal source of its natural behavior.

The Folk Theory of Essences is metaphorical in two ways. First, the very idea of an essence is based on physical properties that compose the basis of everyday categorization: substance and form. For example, a tree is made of wood and has a form that includes a trunk, branches, leaves, roots, bark, and so on. It also has a pattern of change (another kind of form) in which the tree grows from seed to sapling to mature specimen. These are the physical bases on which we categorize an object as a tree: substance, form, and pattern of change. Where an essence is seen as a collection of physical properties, it is seen as one or more of these things. In the case of abstract essences, these three physical properties become source domains for metaphors of essence: Essence As Substance, Essence As Form, and Essence As Pattern Of Change. 

The second way in which the concept of essence is metaphorical concerns its role as a causal source. The intuition is this: If a tree is made of wood, it will burn. Because it has a trunk and stands erect, it can fall over. The idea is that the natural behavior of a tree is a causal consequence of the properties that make it the kind of thing it is: The tree burns because it is made of wood. We have the same intuition about abstract essences, like a person's character. Honest people will tell the truth. Their essence as honest is the causal source of their truth telling. In such cases, we are clearly in the domain of the metaphorical, because we are attributing to a person a metaphorical substance called "character," which has causal powers. An immediate consequence of these two folk theories is the foundational assumption behind all philosophical metaphysics:

Kinds exist and are defined by essences.

It is important to see how a natural desire to know leads so easily to metaphysical speculation, for as soon as we believe that kinds exist, what we shall call the metaphysical impulse takes over. We can apply the Folk Theory of Essences to kinds themselves, from which it follows that there are kinds of kinds and that these kinds of kinds themselves are defined by essences. This iteration is a fateful step; it is the first step toward metaphysics in Western philosophy.

This metaphysical impulse lies at the heart not only of Western philosophy but of all Western science, leading physicists to seek a general field theory, or as it has come to he known, "a theory of everything." In biology, there is a similar quest for a theory of life. Such theories seek to find some essence that characterizes the behavior of things in some general domain of study: physical phenomena, life, the mind, language, and so on. Questions like "What is the mind?" or "What is life?" presuppose the meaningfulness of such a quest for general knowledge. 

Whether we like it or not, we are all metaphysicians. We do assume that there is a nature of things, and we are led by the metaphysical impulse to seek knowledge at higher and higher levels, defined by ever more general categories of things. Once we have started on this search for higher and higher categories and essences, there are three possible alternatives:

  1. The world may not he systematically organized, or we may not he able to know it, above a certain level of generalization, which might even he relatively low in the hierarchy of categories. In other words, there may be a limit to the systematicity of the world or to its intelligibility.
  2. The hierarchy of categories may go on indefinitely, with no level at which an all-inclusive category exists. In this case, the world might be systematic, but not completely intelligible. The process of gaining knowledge of the world would be an infinite, and hence uncompletable, task. 
  3. The iteration up the hierarchy of categories and essences might terminate with an all-inclusive category, whose essence would explain the nature of all things. Only in this case would the world he totally intelligible, at least in principle. 
This third alternative is what we call:

There is a category of all things that exist.

From the Folk Theory of Essences, it follows that this all-inclusive category has an essence, and from the Folk Theory of Intelligibility, it follows that we can at least in principle gain knowledge of that essence. This all-inclusive category is called Being, and its essence is called the Essence of Being.

This third alternative, that the world is completely systematic and knowable, is the most hopeful, least skeptical attitude that someone concerned with seeking general knowledge can take. However, such optimism brings with it a substantial ontological presupposition, that there is a category of Being, and that, since it must have an essence, there is an Essence of Being. As we will see below, there is a profound problem that arises from this ultimate metaphysical impulse, as defined by these four commonplace folk theories. They lead us to ask a set of questions that may not be meaningful. And they give us a view of the world and of knowledge that may he misleading.

To see why this is so, we propose to apply the tools of embodied cognitive science to the emergence of explicit metaphysical thinking in the Western philosophical tradition. The foundational metaphysical projects of Western philosophy were formulated by Aristotle. In early pre-Socratic philosophy, there are hints of this way of thinking about nature that, in Aristotle, finally and explicitly become the quest for an understanding of Being as the ultimate form of knowledge. This sets the stage both for Western science and for theological interpretations of God as Ultimate Being. (pgs 346-9)

George Lakoff & Mark Johnson - Philosophy in The Flesh (1999)

Julho 29, 2013

Philosophy in the Flesh I

[...] philosophers have asked whether time in itself is bounded or unbounded; whether it is continuous or divisible; whether it flows; whether the passage of time is the same for everyone and everything everywhere; whether time is directional and if so whether its direction is a consequence of change, causation, or possibility; whether there can be time without change; whether it loops back on itself; and so on. How we happen to conceptualize time has been seen as irrelevant to such questions. It is assumed that philosophical inquiry can proceed without knowing or caring about the details of how human beings happen to conceptualize what is being studied. (pg.135)

[...] the metaphorical nature of our conceptual system, if unrecognized, can lead philosophers astray. Two things lead to such philosophical errors. First, a philosopher may fail to recognize conceptual metaphor and hence may see metaphorical sentences as literal and take them at face value. Once one takes a metaphor as being literal, the second error is to assume the correspondence theory of truth and therefore to regard the objective world as structured by the metaphor. [...] Augustine dramatized these errors in the eleventh chapter of his Confessions in his discussion of what constitutes a long time. Just when, he asks, is a time long? Is it long when it is present, or when it is past or future? [...] As a literal, metaphysical question about time, there is no answer, since only a short part of a process can occur at any present time. Augustine's answer is interesting. Past, present, and future, he says, do all "exist in some sort in the soul, but otherwhere I do not see them." A cognitive scientist who speaks about minds instead of souls might echo Augustine in contemporary terms, saying that the very idea of "lengths of time" is conceptual, and indeed metaphoric. Our very notion of a "long time" or "long process" is a product of our use of spatial metaphor.

Zeno's paradox of the arrow can also be seen as pointing out the mistake of taking a metaphor to be literal (though he didn't understand it as such). Suppose, Zeno argues, that time really is a sequence of points constituting a time line. Consider the flight of an arrow. At any point in time, the arrow is at some fixed location. At a later point, it is at another fixed location. The flight of the arrow would be like the sequence of still frames that make up a movie. Since the arrow is located at a single fixed place at every time, where, asks Zeno, is the motion? Time, Zeno argues, is not divided up into instants. In our terms, the idea that time is a linear sequence of points is metaphorical, a consequence of times seen as locations in the Moving Observer metaphor. The mistake, once again, is to take what is metaphorical as literal. [...] The appearance of paradox comes from attributing real existence to metaphorical point locations. Zeno's brilliance was to concoct an example that forced a contradiction upon us: literal motion and motion metaphorically conceptualized as a sequence of fixed locations at fixed points in time.

Such observations by Zeno and Augustine are not mere conundrums dreamed up in ancient and medieval philosophy, conundrums that are irrelevant today. They are early insights into the fact that our conceptual systems are not literal. They show that the most common concepts that we use every day and in terms of which we state our truths cannot he taken as literally fitting an objective reality. (pgs.156-158)

many of us would take a sentence like "Time is flowing by rapidly" to be true. Suppose you take this metaphor as being literal; that is, you assume that there really is a "flow" of time past us. This entails that the future is flowing toward us from somewhere and that it presently exists at the future "place." In short, it implies that the future, at least some of it, must exist at the present. [...] If you do not realize the metaphorical nature of the question, you might be led to ask, as some philosophers have, "If time flows, it has to flow at a rate relative to time. Mustn't there be some higher-order time relative to which time itself flows? " The question arises from taking the metaphor literally. To treat it as a deep metaphysical question would be silly. (pg.159)

Philosophers have observed that taking the theory of general relativity as literally true entails that the past, present, and future all exist "at once." That is, the theory seems to suggest determinism and the impossibility of free will or even random probabilistic events, as required by quantum mechanics. Of course, if one recognizes that general relativity uses our common metaphor for conceptualizing time metaphorically in terms of space, one need not reach such metaphysical conclusions. One can see general relativity as metaphorical. This does not make general relativity either false or fanciful or subjective, since its metaphors can still be apt. That is, they can entail non metaphorical predictions that can be verified or falsified. In general, to say that a science is metaphorical is not to belittle it. Because metaphors preserve inferences, and because those inferences can have non metaphorical consequences, one can often test whether or not a scientific metaphor is apt. Indeed, metaphor is what allows mathematical models to be linked to phenomena in the world and to be regarded as scientific theories. (pg.160)

What exactly was proved when Einstein's theory was "confirmed"? Einstein's theory claimed that a large body like the sun should create a significant space-time curvature in its immediate vicinity. If a light ray passed near the sun, it should follow a curved path. This was seen as providing for a test of the gravitational-pull theory versus the space-time-curvature theory. It was assumed that light had no mass; hence there should be no "pull" and the light should travel in a straight line by the sun. But if space-time was curved near the sun, such a light ray should travel along a curved path, mass or no mass. During an eclipse of the sun, the position was observed of a star that could not normally be seen next to the sun when it was shining. If space-time was curved, the light from the star should move in a curved path by the sun, and the star should appear shifted over a few degrees. The measurement was made during a 1919 eclipse, and Einstein's calculation of where the star should appear was verified. Einstein's theory was taken as confirmed-and interpreted literally: There is no force of gravity. What we've been calling that force is space-time curvature. 

Einstein's theory need not have been interpreted literally. One could have said: Einstein has created a beautiful metaphorical system for doing calculations of the motion of light in a gravitational field. The metaphor of space as a temporal dimension allows him to use well understood mathematics to do his calculations. That is a magnificent metaphorical accomplishment. But that doesn't mean we have to understand that theory as characterizing the objectively true nature of the universe. (pg.228)

In superstring theory, all forces-gravitational, electromagnetic, and strong and weak nuclear forces-are conceptualized as curvatures in ten-dimensional space. What this does is allow the same mathematics, Riemannian geometry, to be used to calculate all of what we ordinarily call "forces." But of course, if one takes this theory literally, no forces at all exist as forces. What we used to conceptualize as forces are now all curvatures in ten-dimensional space. If we take superstring theory literally, no forces exist at all. And we live in a radically multidimensional universe, one with ten dimensions! Do we "really" live in a world with ten or more dimensions, many of them very small, with no forces but lots of curvatures in multidimensional space? Or is superstring theory an ingenious and productive technical metaphor that allows all calculations of force to be unified using the same mathematics - Riemannian geometry? These are not mutually exclusive alternatives. From the perspective of the everyday human conceptual system, superstring theory is metaphorical, as is general relativity, as is Newtonian mechanics. To take any of these theories literally is to say that force, and therefore causation, is nonexistent. But to take these scientific theories metaphorically is to allow for the "existence" of causes from our everyday perspective. (pg.230)

One important thing that cognitive science has revealed clearly is that we have multiple conceptual means for understanding and thinking about situations. What we take as "true" depends on how we conceptualize the situation at hand. From the perspective of our ordinary visual experience, the sun does rise; it does move up from behind the horizon. From the perspective of our scientific knowledge, it does not. Similarly, when we lift an object, we experience ourselves exerting a force to overcome a force pulling the object down. From the standpoint of our basic level experience, the force of gravity does exist, no matter what the general theory of relativity says. But if we are physicists concerned with calculating how light will move in the presence of a large mass, then it is advantageous to take the perspective of general relativity, in which there is no gravitational force. It is not that one is objectively true while the other is not. Both are human perspectives. One, the nonscientific one, is literal relative to human, body based conceptual systems. The other, the scientific one, is metaphorical relative to human, body-based conceptual systems. From the metaphorical scientific perspective of general relativity and superstring theory, gravitational force does not exist as an entity-instead it is space-time curvature. From the literal, nonscientific perspective, forces exist. Now, if we take one scientific theory or another as being literally true, and if we insist that there is only one truth and it is the best scientific truth we have, then, as Russell observed, force does not exist, and so neither does causation. If, however, we can allow scientific theories to be recognized for the metaphorical conceptual structures that they are for human beings, then we can allow multiple ways of conceptualizing the world, including both the scientific and nonscientific. Allowing for the multiple perspectives indicated by cognitive analyses allows us to maintain both scientific perspectives, in which causation doesn't exist, and our everyday perspective, in which it does. (pgs.231-2)

When someone asks, "Does causation exist?" that person usually wants to know whether there is a single unified phenomenon (which is called "causation") objectively existing in the mind independent world and operating according to a single logic. Furthermore, he or she assumes that there is a straightforward simple yes-or-no answer. As we have seen, the situation is more complex than that. But the presuppositions lying behind this apparently simple question are massively false. First, causation is a word in a human language and it designates a human category, a radial category of extraordinary complexity. In that complex radial category, there is no set of necessary and sufficient conditions that covers all the cases of causation. Therefore, causation as we conceptualize it is not a unified phenomenon. It does not simply designate an objectively existing category of phenomena, defined by necessary and sufficient conditions and operating with a single logic in the mind-independent world. Because the presuppositions lying behind the question are so far off base, the question has no simple straightforward answer. This eliminates a simpleminded realism that assumes that our language is simply a reflection of the mind-independent world, and hence that such questions are simple and straightforward. But eliminating simpleminded realism does not eliminate all forms of realism, and it does not require either idealism or total relativism. What remains is an embodied realism that recognizes that human language and thought are structured by, and bound to, embodied experience. In the case of physics, there is certainly a mind-independent world. But in order to conceptualize and describe it, we must use embodied human concepts and human language. Certain of those embodied human concepts, the basic-level ones, accord very well with middle-level physical experience and therefore have an epistemic priority for us. It is here that we feel comfortable saying that causation exists for ordinary cases of the direct application of physical force in our everyday lives. The central prototypical case in our basic-level experience gives us no problem in answering the question. He punched me in the arm. He caused me pain. Yes, causation exists. (pg.233)

George Lakoff & Mark Johnson - Philosophy in The Flesh (1999)

Julho 25, 2013

"There is no conflict between causality and randomness or between determinism and probability if we agree, as we must, that scientific theories are not discoveries of the laws of nature but rather inventions of the human mind" -- Athanasios Papoulis, S. Unnikrishna Pillai, Probability, Random Variables and Stochastic Processes (2002)

Junho 25, 2013


Os direitos humanos apenas fazem sentido num contexto social. Um direito que force -- para que seja respeitado nos seus detalhes -- uma sociedade insustentável a médio ou longo prazo, torna-se assim contraditório. Infelizmente não é trivial saber de antemão quais as consequências não intencionais dos direitos que optamos defender e implementar. Ainda mais infelizmente, nada de diferente acontece quando as sabemos.

Junho 23, 2013


Blindsight é um livro de SciFi do autor Peter Watts cujo principal tema é a consciência. Fundamentado em leituras de vários autores de ciência cognitiva -- em especial no trabalho de Thomas Metzinger -- é um livro que faz refletir o leitor sobre o que é ser humano. O livro pode ser lido online em Algumas citações (e eventuais spoilers):

[...] you had a point about language. When you get right down to it, it's a workaround. Like trying to describe dreams with smoke signals. It's noble, it's maybe the most noble thing a body can do but you can't turn a sunset into a string of grunts without losing something. It's limiting.
It's not about trust, Major. It's about location. Nobody gets a good view of a system from the inside, no matter who they are. The view's distorted."
"And yours isn't."
"I'm outside the system."
"You're interacting with me now."
"As an observer only. Perfection's unattainable but it isn't unapproachable"
There was a model of the world, and we didn't look outward at all; our conscious selves saw only the simulation in our heads, an interpretation of reality, endlessly refreshed by input from the senses. What happens when those senses go dark, but the model—thrown off-kilter by some trauma or tumor—fails to refresh? How long do we stare in at that obsolete rendering, recycling and massaging the same old data in a desperate, subconscious act of utterly honest denial? How long before it dawns on us that the world we see no longer reflects the world we inhabit, that we are blind?
"Not talking about case studies. Brains are survival engines, not truth detectors. If self-deception promotes fitness, the brain lies. Stops noticing— irrelevant things. Truth never matters. Only fitness. By now you don't experience the world as it exists at all. You experience a simulation built from assumptions. Shortcuts. Lies. Whole species is agnosiac by default.
You invest so much in it, don't you? It's what elevates you above the beasts of the field, it's what makes you special. Homo sapiens, you call yourself. Wise Man. Do you even know what it is, this consciousness you cite in your own exaltation? Do you even know what it's for?
Maybe you think it gives you free will. Maybe you've forgotten that sleepwalkers converse, drive vehicles, commit crimes and clean up afterwards, unconscious the whole time. Maybe nobody's told you that even waking souls are only slaves in denial.
Make a conscious choice. Decide to move your index finger. Too late! The electricity's already halfway down your arm. Your body began to act a full half-second before your conscious self 'chose' to, for the self chose nothing; something else set your body in motion, sent an executive summary—almost an afterthought— to the homunculus behind your eyes. That little man, that arrogant subroutine that thinks of itself as the person, mistakes correlation for causality: it reads the summary and it sees the hand move, and it thinks that one drove the other.
But it's not in charge. You're not in charge. If free will even exists, it doesn't share living space with the likes of you.
Insight, then. Wisdom. The quest for knowledge, the derivation of theorems, science and technology and all those exclusively human pursuits that must surely rest on a conscious foundation. Maybe that's what sentience would be for— if scientific breakthroughs didn't spring fully-formed from the subconscious
mind, manifest themselves in dreams, as full-blown insights after a deep night's sleep. It's the most basic rule of the stymied researcher: stop thinking about the problem. Do something else. It will come to you if you just stop being conscious of it.
Every concert pianist knows that the surest way to ruin a performance is to be aware of what the fingers are doing. Every dancer and acrobat knows enough to let the mind go, let the body run itself. Every driver of any manual vehicle arrives at destinations with no recollection of the stops and turns and roads traveled in getting there. You are all sleepwalkers, whether climbing creative peaks or slogging through some mundane routine for the thousandth time. You are all sleepwalkers.
Don't even try to talk about the learning curve. Don't bother citing the months of deliberate practice that precede the unconscious performance, or the years of study and experiment leading up to the gift-wrapped Eureka moment. So what if your lessons are all learned consciously? Do you think that proves there's no other way? Heuristic software's been learning from experience for over a hundred years. Machines master chess, cars learn to drive themselves, statistical programs face problems and design the experiments to solve them and you think that the only path to learning leads through sentience? You're Stone-age nomads, eking out some marginal existence on the veldt—denying even the possibility of agriculture, because hunting and gathering was good enough for your parents.
Do you want to know what consciousness is for? Do you want to know the only real purpose it serves? Training wheels. You can't see both aspects of the Necker Cube at once, so it lets you focus on one and dismiss the other. That's a pretty half-assed way to parse reality. You're always better off looking at more than one side of anything. Go on, try. Defocus. It's the next logical step. Oh, but you can't. There's something in the way. And it's fighting back.
A vampire folk tale: "A laser is assigned to find the darkness. Since it lives in a room without doors, or windows, or any other source of light, it thinks this will be easy. But everywhere it turns it sees brightness. Every wall, every piece of furniture it points at is brightly lit. Eventually it concludes there is no darkness, that light is everywhere."

Junho 16, 2013


When Americans not equipped with ecological concepts tried to describe and explain the contrast between their land of opportunity and the old countries from which they had come as immigrants, it became conventional to emphasize the political and ideological contrasts. We tended to forget that the freedoms America offered were not exclusively political. Even more, we forgot that the political differences between America and the older nations in Europe was full of people; America was full of potential. 

When population density was low, human equality is feasible and even probable. Each individual is economically valuable to others; it is, accordingly, hard for others to subordinate him. Class distinctions fade in such circumstances. [William Graham] Sumner tried to get us to see that democracy in Europe as well as in America had been fostered by the New World's low population density. His low density had relieved Old World pressure. Abundant land in another hemisphere influenced the European labor and land markets. Wages went up, food prices were held down, and land rents were kept lower than they would otherwise have been. The power of each European landed aristocrat was reduced by the availability of land elsewhere on the globe, not under his control. Still, Europeans tended to attribute their new freedom to new institutions and new doctrines, not seeing that the institutional and doctrinal changes were responses to the effective reduction of population pressure.

Homo Sapiens mistook the rate of withdrawal of savings deposits for a rise in income. No regard for the total size of the legacy, or for the rate at which nature might still be storing carbon away, seemed necessary. Homo Sapiens set about becoming Homo Colossus without wondering if the transformation would have to be quite temporary. [...] The essence of the drawdown method is this: man began to spend nature's legacy as if it were income. Temporarily this made possible a dramatic increase in the quantity of energy per capita per year by which Homo Colossus could do the things he wanted to do.

Population pressure can be defined as the frequency of mutual interference per capita per day that results from the presence of others in a finite habitat. [...] Population density in the ordinary sense is simply the number of people per square mile. Two nations with equal population density could differ in population pressure if their peoples differed in level of activity. A population using more prosthetic equipment would tend to subject its members to more pressure by doing more things. [In America] more people had been pumped into our finite living space, to make demands upon our finite resources. But our pace of living had also been greatly accelerated. We traditionally welcomed such acceleration as a sign of progress, seldom recognizing that it meant people had increased the ways in which their co-presence resulted in mutual interference. The loss of independence and the failure to understand how it was lost can be illustrated by a fundamental change in the occupational structure of an industrialized nation's labor force.

It is high time to learn that the wisest "use" of coal and oil may be to leave them underground as nature's safe disposal of a primeval atmospheric "pollutant" - carbon. By our ravenous use of fossil acreage to extend carrying capacity we not only prolonged human irruption but also began undoing what evolution had done in getting the atmosphere ready for animals (including man) to breathe, and ready to sustain the kind of climate in which present species (including ourselves) had been evolved. Hundreds of millions of years of evolution had produced the oxygen-rich and nearly carbon-free atmosphere we need [...] We need to accept the earth as it was when our species evolved upon it. had it been different, Homo Sapiens could not have emerged [...] Barring human extinction, there will never come an end to man's need for enlightened self-restraint - the conservation ethic.

OvershootWilliam R. Catton

Junho 10, 2013

Quality Data

Every time an official statistic, like inflation, unemployment of GNP growth is presented in the media, we should remember Campbell's and Goodhart's «laws» and take the data with a grain of salt:

"The more any quantitative social indicator is used for social decision-making, the more subject it will be to corruption pressures and the more apt it will be to distort and corrupt the social processes it is intended to monitor." -- Campbell's law

"When a measure becomes a target, it ceases to be a good measure." -- Goodhart's law

Imagine if there was corruption in the reporting of scientific data. Would, say, Physics or Chemistry advanced as they did? It's much harder to do Science, Economic or any other, in such biased context.

Junho 04, 2013

Tweet discussions

‏@philosophytweet: A reminder of philosophy’s embarrassing failure, after over 2000 years, to settle any of its central issues.
@rudivanetteger: The goal of philosophy is not to provide definite answers, but to provide reasons for individual choices, which it does.

@svarricc: Philosophy is a process not a product. Assess results for value based on the quality of their reasoning.
@rudivanetteger: if you equate philosophy to process of reasoning, does that not reduce philosophy to rhetoric, processing the facts of science?

@svarricc: I never said reasoning had to based on science - although scientific methodology is a popular form.

@rudivanetteger: I spoke of philosophical method: rhetorics and possibly logic, and of scientific results. To me philosophy as process is empty

‏@svarricc: A process is necessarily empty. Its a form for perspective and dialogue but needs content.

‏@rudivanetteger: Does philosophy provide its own content? Or who does?

‏@svarricc: We provide content. We do philosophy. It does not exist without us, and is only as effective as the craftsman who uses it.

Maio 31, 2013

Intuition Pumps quotes by Daniel Dennett

Giving an intentional-stance* interpretation of some sub-personal brain structure is like putting a comment on a few lines of code; when done well, it provides an illuminating label, not a translation into English or other natural language of some formula in Brainish that the brain is using in its information-processing.

(*) the level of abstraction in which we view the behavior of a thing in terms of mental properties [wikipedia]

In general, the cryptographer’s maxim holds: if you can find one solution to a puzzle, you’ve found the only solution to the puzzle. Only special circumstances permit as many as two solutions, but such cases show us that the existence of only one single solution to a question like this is not a metaphysical necessity, but just the immensely probable result of very powerful constraints.

People are much more complicated than either crossword puzzles or computers. They have convoluted brains full of neuromodulators, and these brains are attached to bodies that are deeply entwined with the world, and they have both an evolutionary and a personal history that has embedded them in the world with much more interpenetration than the embedding of a crossword puzzle in a linguistic community. So Ruth Millikan (for instance) is right that given the nature of design constraints, it is unlikely in the extreme that there could be different ways of skinning the cat that left two radically different, globally indeterminate, tied-for-first-place interpretations. Indeterminacy of radical translation* is truly negligible in practice. Still, the principle survives. The reason we don’t have indeterminacy of radical translation is not because, as a matter of metaphysical fact, there are “real meanings” in there, in the head (what Quine called the “museum myth” of meaning, his chief target). The reason we don’t have indeterminacy in the actual world is that with so many independent constraints to satisfy, the cryptographer’s maxim assures us that it is a vanishingly small worry. When indeterminacy threatens in the real world, it is always just more “behavioral” or “dispositional” facts—more of the same—that save the day for a determinate reading, not some mysterious “causal power” or “intrinsic semanticity.” Intentional interpretation almost always arrives in the limit at a single interpretation, but in the imaginable catastrophic case in which dual interpretations survived all tests, there would be no deeper facts to settle which was “right.” Facts do settle interpretations, but it is always “shallow” facts that do the job.

(*)  Radical translation is a term by W. V. O. Quine to describe the situation in which a linguist is attempting to translate a completely unknown language, which is unrelated to his own, and is therefore forced to rely solely on the observed behavior of its speakers in relation to their environment. [wikipedia]

How can meaning make a difference? It doesn't seem to be the kind of physical property, like temperature or mass or chemical composition, that could cause anything to happen. What brains are for is extracting meaning from the flux of energy impinging on their sense organs, in order to improve the prospects of the bodies that house them and provide their energy. The job of a brain is to “produce future” in the form of anticipations about the things in the world that matter to guide the body in appropriate ways. Brains are energetically very expensive organs, and if they can’t do this important job well, they aren’t earning their keep. Brains, in other words, are supposed to be semantic engines. What brains are made of is kazillions of molecular pieces that interact according to the strict laws of chemistry and physics, responding to shapes and forces; brains, in other words, are in fact only syntactic engines. [..] Don’t make the mistake of imagining that brains, being alive, or made of proteins instead of silicon and metal, can detect meanings directly, thanks to the wonder tissue in them. Physics will always trump meaning. A genuine semantic engine, responding directly to meanings, is like a perpetual motion machine—physically impossible. So how can brains accomplish their appointed task? By being syntactic engines that track or mimic the competence of the impossible semantic engine.

Natural selection is an automatic reason-finder; it “discovers” and “endorses” and “focuses” reasons over many generations. The scare quotes are to remind us that natural selection doesn't have a mind, doesn't itself have reasons, but it is nevertheless competent to perform this “task” of design refinement. This is itself an instance of competence without comprehension. Let’s just be sure we know how to cash out the scare quotes. Consider a population with lots of variation in it. Some members of the population do well (at multiplying); most do not. In each case we can ask why. Why did this one have surviving offspring while these others did not? In many cases, most cases, there is no reason at all; it’s just dumb luck, good or bad. But if there is a subset, perhaps a very small one, of cases in which there is an answer, a difference that happens to make a difference, then what those cases have in common provides the germ of a reason. This permits functionality to accumulate by a process that blindly tracks reasons, creating things that have purposes but don’t need to know them. The Need to Know principle reigns in the biosphere, and natural selection itself doesn't need to know what it’s doing. So there were reasons before there were reason-representers. The reasons tracked by evolution I have called “free-floating rationales," [...] There are reasons why trees spread their branches, but they are not in any strong sense the trees’ reasons. Sponges do things for reasons; bacteria do things for reasons; even viruses do things for reasons. But they don’t have the reasons; they don’t need to have the reasons. There are reasons aplenty for these behaviors, but in general, organisms need not understand them. They are endowed with behaviors that are well designed by evolution, and they are the beneficiaries of these designs without needing to know about it. This feature is everywhere to be seen in nature, but it tends to be masked by our tendency, adopting the intentional stance, to interpret behavior as more mindful and rational than it really is.

Then what might the self be? I propose that it is the same kind of thing as a center of gravity, an abstraction that is, in spite of its abstractness, tightly coupled to the physical world. [...] It may be a “theorist's fiction,” but it is a very valuable fiction from which a lot of true predictions can be generated. [...] What then is a center of narrative gravity? It is also a theorist’s fiction, posited in order to unify and make sense of an otherwise bafflingly complex collection of actions, utterances, fidgets, complaints, promises, and so forth, that make up a person. It is the organizer of the personal level of explanation. Your hand didn't sign the contract; you did. [...] In the same way that we can simplify all the gravitational attractions between all the parts of the world and an obelisk standing on the ground by boiling it down to two points, the center of the earth and the center of gravity of the obelisk, we can simplify all the interactions—the handshakes, the spoken words, the ink scrawls, and much more—between two selves, the seller and the buyer, who have just completed a transaction. Each self is a person, with a biography, a “backstory,” and many ongoing projects. Unlike centers of gravity, selves don't just have trajectories through space and time; they gather as they go, accumulating memories and devising plans and expectations.

Maio 18, 2013


Um magnífico resumo e resposta à cansativa resistência da direita conservadora:


No caso da adopção  homossexual, os adversários da tendência têm de provar que casais homossexuais  são sempre um ambiente nefasto para uma criança se desenvolver. Assim mesmo, no geral, porque as leis são gerais. Ora, postas as coisas neste pratos , a tarefa é impossível.
A impossibilidade decorre do principal, e, do meu ponto de vista,  único ,  argumento:  toda  a criança necessita de um pai e de uma mãe. Em Portugal uma pessoa solteira radical pode adoptar, o que, só por si, já parece contrariar o argumento, mas  há mais. Notem:

It is estimated that there are 500,000 children in foster care nationally, and 100,000 need to be adopted.2 But last year there were qualified adoptive parents available for only 20,000 of these children.3 Many of these children have historically been viewed as “unadoptable” because they are not healthy white infants.

Ou seja, dezenas de milhar de crianças ficam sem um pai e uma mãe. Podemos especular por que motivo tantos casais heterossexuais católicos e bem na vida não adoptam estas crianças, mas as coisas são o que são  e já dizia Ratzinger que falta muita Igreja na vida quotidiana. O importante é outra coisa.  Os adversários da adopção gay são obrigados  a dizer isto: é preferível ficar institucionalizado do que ser adoptado por duas mulheres. Dito de outra forma, têm de dizer isto: o superior interesse da criança fica sempre melhor defendido com ela  a crescer numa instituiçao do que com qualquer casal homossexual.
Pode o Estado saber se é melhor ficar institucionalizado do que ser adoptado por duas Marias?  Claro que não. O que o governo pode saber, via  comissões de peritos,  é se cada casal candidato tem ou não condições para adoptar. E pode vetar casais  gays.
Já escrevi mutas vezes e em muitos lugares ( livros, artigos e blogues) que entendo que a família tradicional é a melhor combinação para uma criança crescer. O que nunca escreverei é que para uma criança, qualquer coisa é preferível a ser criada por duas irmãs mais velhas  ou por uma tia e uma avó ( como já aconteceu tantas vezes). O “superior interesse da criança” é o laço humano, não  a irritação pela militância LGBT.


Maio 08, 2013

Drive your car

"The categories and classes we construct are simply the semantic sugar which makes the reality go down easier. They should never get confused for the reality that is, the reality which we perceive but darkly and with biased lenses. The hyper-relativists and subjectivists who are moderately fashionable in some humane studies today are correct to point out that science is a human construction and endeavor. Where they go wrong is that they are often ignorant of the fact that the orderliness of many facets of nature is such that even human ignorance and stupidity can be overcome with adherence to particular methods and institutional checks and balances. The predictive power of modern science, giving rise to modern engineering, is the proof of its validity. No talk or argumentation is needed. Boot up your computer. Drive your car." -- Razib Khan

Abril 07, 2013

Escalas 1:1 antes de Jorge Luís Borges

‘That’s another thing we’ve learned from your Nation,” said Mein Herr, “map-making. But we’ve carried it much further than you. What do you consider the largest map that would be really useful?”

“About six inches to the mile.”
“Only six inches!” exclaimed Mein Herr. “We very soon got to six yards to the mile. Then we tried a hundred yards to the mile. And then came the grandest idea of all! We actually made a map of the country, on the scale of a mile to the mile!”
“Have you used it much?” I enquired.
“It has never been spread out, yet,” said Mein Herr: “the farmers objected: they said it would cover the whole country, and shut out the sunlight! So we now use the country itself, as its own map, and I assure you it does nearly as well.”
Lewis CarrollSylvie and Bruno Concluded, 1893

Março 21, 2013

Os Despojados II

  • It is of the nature of idea to be communicated: written, spoken, done. The idea is like grass. It craves light, likes crowds, thrives on crossbreeding, grows better for being stepped on.
  • It is hard, however, for people who have never paid money for anything to understand the psychology of cost, the argument of the marketplace.
  • You can’t crush ideas by suppressing them. You can only crush them by ignoring them. By refusing to think, refusing to change.
  • What drives people crazy is trying to live outside reality. Reality is terrible. It can kill you. Given time, it certainly will kill you. The reality is pain [...] But it’s the lies, the evasions of reality, that drive you crazy.
  • The individual cannot bargain with the State. The State recognizes no coinage but power: and it issues the coins itself.
  • We came from a great distance to each other. We have always done so. Over great distances, over years, over abysses of chance. It is  because he comes from so far away that nothing can separate us. Nothing, no distances, no years, can be greater than the distance that's already between us, the distance of our sex, the difference of our being, our minds; that gap, that abyss which we bridge with a look, with a touch, with a word, the easiest thing in the world.
Ursula K. LeGuin -- The dispossessed