True understanding is possible only when we are fully conscious of our thought, not as an operative observer on this thought, but completely and without the intervention of a choice.
[Prudence] is the virtue of that part of the intellect [the calculative] to which it belongs; and . . . our choice of actions will not be right without Prudence any more than without Moral Virtue, since, while Moral Virtue enables us to achieve the end, Prudence makes us adopt the right means to the end.
Mind is a duality; it is always split. There is no single point on which the mind agrees in totality. Half of the mind will agree and half of the mind will disagree, and whatever you choose, you are choosing only the half. The remaining half is going to take revenge. The unchosen part, the left over, will wait for its chance to show you that whatever you have chosen is wrong. But it does not matter which part you choose. Choice itself is wrong.
Constancy has nothing virtuous in itself, independently of the pleasure it confers, and partakes of the temporizing spirit of vice in proportion as it endures tamely moral defects of magnitude in the object of its indiscreet choice.