It is because we _know_ a thing to be good that we wish it, and knowing it, we cannot help wishing.

Conscience, as the name implies, is allied to knowledge.

Reason gives the law to will.
After a long disquisition about the passions and the whole appetitive side of human nature, over which Reason is called to rule, he is brought to the subject of virtue.

He is Aristotelian enough to describe virtue as _habitus_--a disposition or quality (like health) whereby a subject is more or less well disposed with reference to itself or something else; and he takes account of the acquisition of good moral habits (_virtutes acquisitae_) by practice.

But with this he couples, or tends to substitute for it, the definition of Augustin that virtue is a good quality of mind, _quam Deus in nobis sine nobis operatur_, as a ground for _virtutes infusae_, conferred as gifts upon man, or rather on certain men, by free grace from on high.