Sidis entertains the idea that life originated on Earth from asteroids (as put forth by Lord Kelvin and Hermann von Helmholtz) while describing his theory as a synthesis of the mechanical and vitalist life models. Sidis also claims that stars are "alive" and go through an eternally repeating light-dark cycle, with the second law reversing in the dark portion of the cycle. Sidis' theory was dismissed upon release, only to be discovered in an attic in 1979. Buckminster Fuller (a Sidis classmate) wrote to Gerard Piel in response to this discovery: Imagine my surprise and delight when I was handed a xerox of Sidis' 1925 book, in which he predicted the black hole. His book, The Animate and the Inanimate is a tremendous cosmological work. I find him focusing on the same topics that fascinate me and reaching roughly the same conclusions that I have published in SYNERGETICS and will publish in SYNERGETICS Volume II, which has already gone to press. As a Harvard man of a later generation, I hope you are as excited as I am that Sidis went on to do the most magnificent thinking and writing after college.

This is one of the few works by Sidis that was not written under a pen name. In The Animate and the Inanimate, Sidis says that the universe is endless and has parts where the laws of physics are backward, called "negative tendencies." Following these are sections where the laws of physics are forward-looking, known as "positive tendencies," which change over time. He claims there was no "origin of life"; life has always existed and only evolved.