Since he lectured on the subject in 1919, Farwell remained adamant throughout his life that the sonata form was one of the most important musical "laws" discovered by humans. By the 1940s he had been making connections between sonata form and the symbolic geometry of the "tree of life," found in Jewish Kabbalah. In 1942 Farwell published his essay The Sonata Form and The Cabbala
My graphic summary of Farwell's sephirotic philosophy

My graphic summary of Farwell's sephirotic philosophy

Farwell presents the “tree of life” and the sonata form as identical models that engage both the psyche of the “individual man” as well as of the Universe. Farwell's aim was to unite with the Universal. “That is to say,” Farwell writes, “at his highest level [the composer] holds, deeply subjective and only vaguely discernable to himself, the ideal archetype of that which he is to create. This is the most highly mystical and inscrutable part of his nature.” And for Farwell, the sonata was one such archetype. 
In this form we begin with a “first theme,” which from childhood we are taught has a masculine character. This is followed, with due linkage, by a second theme having, by comparison, a feminine character. When these two themes are properly established, we then have the “development section,” or “free fantasia,” where the two themes are pre-eminently subjected to a free play of formative principles to the ends of beauty, and eventually victorious and splendid rebirth. And finally we have a recapitulation which goes back to the beginning and reviews the whole first division with its two themes, and, with the development of the extended coda, reviews the preceding matter in still further aspects.
Farwell then corresponds the four Hebrew letters of the Divine Name (IHVH) with the formal sections of the sonata. The “exposition” section of the sonata is divided into two, in order to reflect its masculine and feminine expressions. And so the exposition is identical to I and H. The “development” section is identical with V. And the “recapitulation” is identical to the H. In other words, Farwell is taking the sonata form, projecting esoteric symbolism upon it, and using this form as a transformative meditation, one that aided his creative process.