This period in Athens, between 335 and 323 BC, is when Aristotle is believed to have composed many of his works. He wrote many dialogues, of which only fragments have survived. Those works that have survived are in treatise form and were not, for the most part, intended for widespread publication; they are generally thought to be lecture aids for his students. His most important treatises include "Physics", "Metaphysics", "Nicomachean Ethics", "Politics", "On the Soul" and "Poetics". Aristotle studied and made significant contributions to "logic, metaphysics, mathematics, physics, biology, botany, ethics, politics, agriculture, medicine, dance, and theatre."