[4][5][6][7] Throughout his life, Sinnott was a prolific author; he wrote ninety scientific articles and many textbooks.

In his teaching, Sinnott stressed the idea of scientific discovery and the importance of making careful measurements and correctly interpreting data.

[10][11] In his book Biology of Spirit (1955) he used the term Telism which he defined as "the philosophy of goals-a belief that what is important is not the push and drive of a living system but the drawing power of a goal, conscious or unconscious, that in some is established in it".

[16][17] He was criticized by Leo Koch for making metaphysical statements in his science books, he stated for example "The Principle of Organization is far more than a scientific concept.

"[12] In his book Cell and Psyche (1950) he argued that mind and matter are two aspects of the same phenomenon and that purpose exists in all organisms as it is built into the genotype and the protoplasm.