Abstract
This is partly a book about Aristotle’s four causes (material, formal, efficient, and final cause), partly a systematic discussion of the relation between form and matter, causation, and teleology. Its overall aim is to show that the four causes form a system, so that the form of a natural thing relates to its matter as the final cause of a natural process relates to its efficient cause. It reaches two highly distinctive conclusions. The first is that the formal cause or essence of a thing is not a property but a generic thing. The second is that the final cause of a process is not its purpose but the course that processes of its kind typically take.