I am trying to grasp the concept of teleology from an Aristotelian-Thomistic point of view. The following quotes from David Oderberg's Teleology: Inorganic and Organic define it clearly:
"The idea that all objects have a natural tendency to some kind of motion or behaviour characteristic of their essence."
"the idea of a characteristic tendency towards a certain kind of operation of behaviour, and resistance to other kinds of behaviour or causes contrary to the thing's nature."
I also found this abstract, which attempts a definition:
"the Humean world is one in which all the elements are loose and separate, “just one little thing and then another”, and in which any causal and lawful relations are to be discovered as patterns of regularity. In contrast, theories that hark back to Aristotle emphasize a more connected world. Things can have powers or dispositions towards certain outcomes as an essential part of their natures. Indeed, things can be classified as what they are according to the powerful natures they have."
There is also this lovely paper that precisely identifies the distinction between Aristotelian-Thomistic final causality and Humean causality:
"according to the Aristotelian conception, causes are conceived as the active originators of a change that is brought about for the sake of some end."
"the Aristotelian-scholastic conception, according to which causes are the active initiators of a change, and the scientific conception, according to which causes are the inactive nodes in a law-like implication chain."
"According to I, 'A is the cause of B' means 'A is the initiator of a change in B'; according to II, 'A is the cause of B' means 'Given the occurrence of B, A must necessarily have occurred.'"