That is plain.
The law of contradiction. And if you suppose something which pulls a thirsty soul away from drink, that must be different from the thirsty principle which draws him like a beast to drink; for, as we were saying, the same thing cannot at the same time with the same part of itself act in contrary ways about the same.
Impossible.
No more than you can say that the hands of the archer push and pull the bow at the same time, but what you say is that one hand pushes and the other pulls.
[C] Exactly so, he replied.
And might a man be thirsty, and yet unwilling to drink?
Yes, he said, it constantly happens.
And in such a case what is one to say? Would you not say that there was something in the soul bidding a man to drink, and something else forbidding him, which is other and stronger than the principle which bids him?
I should say so.
[D]The opposition of desire and reason. And the forbidding principle is derived from reason, and that which bids and attracts proceeds from passion and disease?