It is known that people can think in a minute's time what they cannot express in speaking or writing in the space of an hour. For while thinking, they are enclosing everything together under a general, governing mental image, and all the concordant details flow appropriately to them from the memory, forming part of their general idea. Nevertheless, that general is such that they see the chain of thoughts that follow. Even if only obscurely, they still see it, and join it together, because they draw a conclusion. This, too, shows what a general is that governs the least parts.