Averroism was a philosophical trend among scholastics in the late 1200s based on Averroës' interpretations of Aristotle. The main philosophers involved were Sigerus of Brabant and Boëthius of Dacia.

The main ideas of Averroism (found in Averroës commentaries to Aristotle) were:

• that the world was eternal
• the soul was divided into two parts, one individual part and one divine part
• that the individual soul was not eternal and
• that all humans at the basic level shared one and the same divine soul, also known as monopsychism
• the resurrection of the dead is not possible (Boëthius of Dacia)

This standpoint resulted in two condemnations in 1270 and 1277, this time by Bishop Etienne Tempier of the Catholic church. Tempier specified 219 different unacceptable Averroist theses. To resolve the problem, Sigerus of Brabant tried to claim that there existed a "double truth": one factual or "hard truth" which is reached by science and philosophy, and one "religious truth" reached through religion. This idea had not originated in Averroës.

The later philosophical concept of Averroism was the idea that the philosophical and religious worlds are separate entities. However, upon scrutinizing the 219 theses condemned by Tempier, it was obvious that not many of them originated in Averroës, so for a while other terms were commonly used to refer to the actual philosophical movement started by Sigerus and Boëthius: Radical Aristotelianism or Heterodox Aristotelianism are other words used for this movement, but nowadays most scholars call it Averroism.

Thomas Aquinas specifically attacked the doctrine of monopsychism in his book De unitate intellectus contra Averroistas. In this context, the word Averroism is used correctly.

Although condemned in 1277 many Averroistic theses survived during the 16th century and can be founded in the philosophy of Giordano Bruno or Pico della Mirandola. These theses talk about the superiority of philosophers to the common people and the relation between the intellect and human dignity.