It is right, then, to say that by doing what is just a man becomes just, and temperate by doing what is temperate, while without doing thus he has no chance of ever becoming good.

But most men, instead of doing thus, fly to theories, and fancy that they are philosophizing and that this will make them good, like a sick man who listens attentively to what the doctor says and then disobeys all his orders. This sort of philosophizing will no more produce a healthy habit of mind than this sort of treatment will produce a healthy habit of body.

We have next to inquire what excellence or virtue is.