Below, a few selected quotes from the book:

Any living situation in which an artist finds material pertinent to his own temper is a proper situation for art.

… whatever one paints must be constantly re-examined, torn apart, if that seems to be indicated, in the light of new attitudes or new discovery. If one has set for himself the position that painting shall not misconstrue his personal mode of thinking, then he must be rather unusually alert to just what he does think.

If the artist, or poet, or musician, or dramatist, or philosopher seems somewhat unorthodox in his manner and attitudes, it is because he knows—only a little earlier than the average man—that orthodoxy has destroyed a great deal of human good, whether of charity, or of good sense, or of art.

Nonconformity is the basic pre-condition of art, as it is the pre-condition of good thinking and therefor the growth and greatness in a people.

… art can be pushed to meaningless extremes. And it is a constant struggle to wrench out of the paint tube something that is still newer than new. Of course when such work becomes dated, its emptiness emerges, for nothing is so hard to look at as the stylish, out of style.

If a painting is to be at all interesting, it is the very absence of formula that will help make it so. If forms are reduced to have a certain common quality, a unity, that is so because they proceed from a personal vision, because they are affected and shaped by the aberrations or the excellence of a single mind. The personality is an axis which gives its radial direction to everything which issues from it.

Style today is the shape of one’s specific meanings. It is developed with an aesthetic view and a set of intentions. It is not the how of painting, but the why. To imitate or to teach style alone would be a little like teaching a tone of voice or personality.