As mentioned earlier, Theano wrote quite a bit of treatises, which is a any sort of written work that deals formally and systematically in a certain subject. Theano wrote a few of these treatises which involved medicine, physics, mathematics, and psychology. During Theano's writing period she brought a few historical writings for us, which include "Cosmology, The Theorem of the Golden Mean, The Theory of Numbers," and "The Construction of the Universe." Out of all these writings it is said that, "The Theorem of the Golden Mean," is the most conflicted writing due to the fact that Theano had made many arguable points. Because Theano wrote about the universe and planets in this writing, there might be some arguable points that other philosophers can make, for example Theano states that the stars are unable to move, but Aristotle would say the opposite, and say that they are able to move. The Theorem of the Golden Mean, is still used today and is one of Theano's most important writings.