Hylas next tries to bring Philonous down with the problem of evil. If God causes everything, Hylas points out, He must cause evil too. Every time an innocent child dies, for instance, God must be to blame. But Philonous reminds Hylas that his view is no more susceptible to this worry than any other good Christian view. On any of these views, God is responsible for all that happens in the world, and He is no more guilty if he acts without the intervening instrument of matter than if he acts with this intervening instrument. In any case, Philonous continues, there really is no problem here. We all have our own will and so can be guilty of our own sins.
Hylas drops the issue of evil, and moves onto another problem. Say we see an oar in water, he says, and it appears bent to us. We then lift it out and see that it is really straight; the bent appearance was an illusion caused by the water's refraction. On Philonous' view, though, we cannot say that we were wrong about the initial judgement; if we perceived the stick as bent then the stick had to have been bent. Similarly, since we see the moon's surface as smooth we cannot really say that the moon's surface is not smooth; the way that it appears to us has to be the way it is. Philonous has an answer to this worry as well. While we cannot be wrong about the particular idea, he explains, we can still be wrong in our judgement. Ideas occur in regular patterns, and it is these coherent and regular sensations that make up real things, not just the independent ideas of each isolated sensation. The bent stick can be called an illusion, therefore, because that sensation is not coherently and regularly connected to the others. If we pull the stick out of the water, or we reach down and touch the stick, we will get a sensation of a straight stick. It is this coherent pattern of sensations that makes the stick. If we judge that the stick is bent, therefore, then we have made the wrong judgement, because we have judged incorrectly about what sensation we will have when we touch the stick or when we remove it from the water.
Hylas next asks how God could contain all of our ideas and still be perfect. If God contains all our ideas, then he has pain, and to feel pain is an imperfection. Philonous corrects Hylas: God does not sense anything, his ideas are purely intellectual. It is only when we glimpse the ideas in God that they are conveyed as sensory perception.
Hylas moves on quickly to another idea: what about gravity? The law of gravity tells us that the quantity of motion in any body is proportional to the matter plus the velocity. Philonous points out that this way of phrasing the law is question-begging. You could just as easily say that gravity is proportional to the magnitude and solidity of the object, both of which qualities are mind- dependent.
Berkeley presents a very strange and very brief analysis of body. The reason that we must perceive ideas through sensory perception, as opposed to God who has a pure intellectual perception of ideas, Philonous explains, is because our spirit is tied to a body, whereas God's is not. A body, Philonous then goes on to explain, is just a collection of ideas, of course. So the connection between our sensations and corporeal motions is just a correspondence between two sets of ideas.
This picture eliminates the sticky problem of mind-body interaction but it does raise another puzzle: why do we have body at all? On this account, it seems to make no sense that God would have given us a body. It does nothing good for us, as far as Berkeley indicates, and it apparently does something bad: it prevents us from perceiving ideas in the most perfect way, and forces us to have sensations instead. In addition, we can also ask: if body is nothing but another one of our ideas, why does it have such an extreme effect on the way that we can perceive ideas? Why should it be that, because we have this extra idea of body, which is somehow connected to our idea of spirit, we can only sensorily perceive ideas? Berkeley fails to address these problems, and they pose a considerable challenge to his system.
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