Jacques Barzun (From Dawn to Decadence) on Dorothy L. Sayers:

Like Henry James, who gave a full-blown theory of the novel, Sayers laid down that of the detective tale, using her scholarship by turns seriously and with humor. Interviewed on the subject, she once manifested her forthright ways of speech: “imbeciles and magazine editors” would ask her to discuss crime fiction “from the woman’s point of view. To such demands one can only say ‘Go away and don’t be silly.’ You might as well ask what is the female angle on the equilateral triangle.” On aesthetics at large she wrote an extraordinary little book, The Mind of the Maker. Its thesis is that the ordinary experience of making anything – creating art or applying workmanship to any object – corresponds to the meanings symbolized by the Trinity. First comes the creative Idea, which foresees the whole work as finished. This is the Father. Next the creative Energy, which engages in a vigorous struggle with matter and overcomes one obstacle after another. This is the Son. Third is the creative Power of the work, its influence on the world through its effect on the soul of the user-beholder. This is the Holy Spirit. All three are indispensable to completeness as they unite in the work.

The Mind of the Maker at IWP Books.