Sean Carroll in Preposterous Universe:
“Teleology” is a naughty word in certain circles — largely the circles that I often move in myself, namely physicists or other scientists who know what the word “teleology” means. To wit, it’s the concept of “being directed toward a goal.” In the good old days of Aristotle, our best understanding of the world was teleological from start to finish: acorns existed in order to grow into mighty oak trees; heavy objects wanted to fall and light objects to rise; human beings strove to fulfill their capacity as rational beings. Not everyone agreed, including my buddy Lucretius, but at the time it was a perfectly sensible view of the world.
These days we know better, though the knowledge has been hard-won. The early glimmerings of the notion of conservation of momentum supported the idea that things just kept happening, rather than being directed toward a cause, and this view seemed to find its ultimate embodiment in the clockwork universe of Newtonian mechanics. (In technical terms, time evolution is described by differential equations fixed by initial data, not by future goals.) Darwin showed how the splendid variety of biological life could arise without being in any sense goal-directed or guided — although this obviously remains a bone of contention among religious people, even respectable philosophers. But the dominant paradigm among scientists and philosophers is dysteleological physicalism.
However. Aristotle was a smart cookie, and dismissing him as an outdated relic is always a bad idea.