In his book Flight from the Absolute Canadian scholar Paul Gosselin lists a dozen or so that are most prominent. Here's a partial listing which I've taken the liberty of putting in my own words:
- Humans are solely the product of evolutionary processes and as such are a part of nature and can claim no special status. This is an assumption postmoderns have borrowed from modernity.
- Human nature is not fixed but is subject to evolutionary change caused by natural, cultural and political forces.
- There is no source of objective moral laws, no divine moral authority, and thus no absolute universal moral truth or objective, absolute truth of any kind.
- Since truth is a cultural construct, all cultures and all religions have their own valid truth perspectives and all should be tolerated and celebrated.
- Since truth is subjective, one's feelings are as reliable a guide for life as is human reason.
- The material world is not all there is. The supernatural exists and is worthy of our attention, although traditional Christian doctrines are often too constricting.
- The idea of Western superiority and the concept of Progress must be rejected.
- Salvation and the meaning of life is found in individual self-fulfillment. Man is morally autonomous, free to pursue his fulfillment in any fashion he chooses.
- No behavior, especially sexual behavior, is wrong as long as it's fulfilling to the individual and doesn't hurt others, at least not too much. No one has the right to judge the choices of others, especially their sexual choices.
- Feelings of guilt should be seen as vestiges of an obsolete past and ignored or suppressed.
Everything else follows, psychologically if not exactly logically, from that assumption. Indeed, it all follows from one word in #1, the word solely.
If man is not just the product of blind natural processes, but rather is the intended product of an intelligent agent who perhaps works through natural processes, then everything else in the postmodern worldview can be called into question. In fact, it may not be too much to say that the majority of our differences today arise from #1 and the word solely.
It's amazing how much a single, solitary word can entail.