As statesmen [or students of Politics], then, we must inquire into the nature of the soul, but in so doing we must keep our special purpose in view and go only so far as that requires; for to go into minuter detail would be too laborious for the present undertaking.

Now, there are certain doctrines about the soul which are stated elsewhere with sufficient precision, and these we will adopt.

Two parts of the soul are distinguished, an irrational and a rational part.

Whether these are separated as are the parts of the body or any divisible thing, or whether they are only distinguishable in thought but in fact inseparable, like concave and convex in the circumference of a circle, makes no difference for our present purpose.