the pull and push of ethical systems

Intuitively, there are two basic desiderata for a system of ethics:

• that the system prescribes behaving well toward other people, or prescribes behaving with respect for certain principles; and
• that the system provides a rationally compelling reason to behave as it prescribes.
  

Satisfying either of these is notoriously easy; satisfying both at once is notoriously hard. Nozick (1981) calls these desiderata the pull and push, respectively, of ethical systems, and points out that the main theoretical problem is to connect the two. Historically, humankind has often resorted to fantasies that bridge the gap: divine incentives (usually deferred to a supposed afterlife), karma (what goes around supposedly comes around), reincarnation (in a form that depends on your prior conduct), or an exaggeration of the extent to which one’s conduct causes reciprocity. Good and Real, Gary Drescher