Aristotle on the Origin of Causes

The following is an essay I turned in for my Aristotle class. 

Explain Aristotle’s argument in Physics Book VIII, Chapter 4. Your explanation should make clear not just what problem Aristotle addresses but why it is a pressing problem for him.

The problem that Aristotle wants to address is the origin of causes (256a). To flesh this out, he makes a few distinctions. The first distinction is between accidental and essential motion (254b10). Accidental motion would be things like a woman healing a patient. The woman heals a patient not because she is a woman, but because she has healing medical knowledge. That she is a woman is only an accident of the cause. Essential motion on the other hand is motion with appropriate links to causes, such as being healed by a doctor. It is essentially the doctor who heals me as a doctor, not for any other feature in addition to their doctor status. A second distinction he makes is between things which are moved by either something within itself or from without itself (254b15). A motion which is caused from within itself is something like an animal who walks. The act is not done because of some external source, like a strong enough wind moving the legs, but because, internally, the animal chooses to walk itself. The third distinction he makes is between natural and unnatural causes (254b15). There is a correspondence between an internal motion with natural causes, and external motion with unnatural causes. Natural is what properly belongs to the thing, whereas unnatural is what does not properly belong to the thing. However, when considering parts of the animal, or any thing in general, the motion of the parts are often unnatural (254b20). For example, a fish which jumps out of water, while in the air, motions its tail unnaturally. There is no water resistance in the air which allows it to propel. But when in water, such tail motions are natural. Given these considerations, Aristotle thinks it's evident that whatever is in motion derives its motion from something (254b25). Accidental causes and unnatural causes are obvious examples of motion being derived from elsewhere. This isn’t as evident for causes which are natural and internal, however (255a). This needs further explanation for Aristotle. 

The problem that needs explaining is this: how can something which is naturally caused go against its own nature? If a natural cause can have unnatural effects, it seems we have a contradiction on our hands. Aristotle’s answer is that in such cases, the causes do not really derive from themselves, and he gives a few reasons for this. First, motion being derived from oneself applies only to living things, and the examples he is considering, such as light and heavy, are not themselves living things (255a5). Second, if things could have contrary powers, then one would need to experience a thing doing an act at one point and then doing the contrary at some other point (255a5). But since this is not experienced, then they don’t have that internal power. Third, such substances are impassive (255a15), that is to say, it moves because of a living thing, like a bowling ball doesn’t roll down the alley, but only because I, a living thing, have moved it so. Even if there is contact between my hand and the ball, these are not continuous things. There is a division between us, so likewise there must be a distinction between what is caused and what is causally derived. 

This has implications for Aristotle’s analysis of potency. Some potencies are said to be essential and others accidental (255a25). This is the cause of confusion which needed to be addressed (255a30). So a clarification of potencies will clarify the answer. So if we were to say I do not know the answer to a math problem, this can be said in two different ways. It can be said that I don’t know the answer because I don’t know how to do math, and it can be said that I don’t know the answer because I haven’t considered the problem, even though I could figure it out (255b). Similarly, something has the potential to burn me, while it is cold because it doesn’t have that power to burn me, or while it is hot and so has that power but has yet to make contact with me (255b5). So, applying these distinctions back to what is the origin of causes, we can coherently speak of these things. For example, when a ball hits the wall, and we ask what causes the rebound, we need not be confused about whether the man or wall causes it. We can say that the man caused it essentially, and the wall accidentally. And if that is the case, then it still remains that whatever is moved must be moved by something else.