Four causes
Aristotle was not the first philosopher to engage in a causal investigation of the world around us. Quite the opposite: from the very beginning, and independently of Aristotle, the investigation of the natural world consisted in the search for the relevant causes of a variety of natural phenomena. From the Phaedo, for example, we learn that the so-called “inquiry into nature” consisted in a search for “the causes of each thing; why each thing comes into existence, why it goes out of existence, why it exists” [1].
Background
Both in the Physics and in the Metaphysics Aristotle places himself in direct continuity with this tradition. At the beginning of the Metaphysics, Aristotle offers a concise review of the results reached by his predecessors [2]. From this review we learn that all his predecessors were engaged in an investigation that eventuated in knowledge of one or more of the following causes: material, formal, efficient, and final cause. However, Aristotle makes it very clear that all his predecessors (no one excluded) merely touched upon these causes [3]. He equates them to boxers who lack boxing technique: while sometimes they can throw a nice punch, any punch that lands is only a lucky one [4]. In other words, even when his predecessors had valuable insights into causality, they spoke without having proper knowledge. His view is that they spoke about causes without making the relevant distinctions and without conveying clarity[5].
By Aristotle’s lights, all his predecessors engaged in their causal investigation without a firm grasp of causality. They lacked a complete understanding of the range of possible causes and their systematic interrelations. Put differently, their use of causality was not supported by an adequate theory of causality. According to Aristotle, this explains why their investigation, even when it resulted in important insights, was never entirely successful.
This insistence on the doctrine of the four causes as an indispensable tool for a successful investigation of the world around us explains why Aristotle provides his reader with a general account of the four causes. This account is found, in almost the same words, inPhysics II 3 and Metaphysics V 2.