that they depend upon a cause.’

His question: ‘Do you claim that this is self-evident or that it requires reasoning?’

We reply: ‘We claim that it is self-evident. Suppose we take a person of sound mind who has never engaged in these disputes and ask him to consider whether one pan of a balance could outweigh the other for no reason whatsoever. Sound reason would clearly reject this.

Likewise, if he entered a wilderness where he found no buildings at all, then entered it again and found a lofty, firmly constructed building, he would necessarily know that a builder and maker existed. Similarly, if he perceived a sound or movement, he would necessarily know that something was producing the sound or moving. Even children necessarily know this: when they find something in a place where they did not expect it, their sound natural dispositions lead them to seek whoever put it there. This shows us that such knowledge is self-evident.’

His statement: ‘If we present to reason the proposition that one is half of two, and also the proposition that a contingent thing