Aristotle

Nicomachean Ethics

Aristotle

The good life is activity in accordance with virtue, and virtue is a disposition trained by habit rather than taught by rule.

Assumes no Greek and no prior Aristotle, though knowing that eudaimonia means flourishing saves early confusion

Physics

Aristotle

Defines nature as an internal principle of change and sets out the four causes, arguing that explaining a thing means saying what it is for as well as what it is made of.