It is widely acknowledged that John Buridan was the most influential philosopher at the University of Paris in the 14th century. This paper aims to show Buridan's materialist account about human beings found in his commentary on Aristotle's De anima, in which three competing theories are discussed: the opinions of Alexander of Aphrodisias, and Averroes, and the position of the Catholic faith. Buridan argues in favor of Alexander that the human soul inheres in matter, is educed from the potency of matter, is extended like matter, is multiplied, and is generated and corruptible. Thus Buridan does uphold materialism which affirms that the human soul is as material as the soul of the animal, with no special ontological status. However, he adds that the materialism, which is opposed to faith, must be always denied. This leads us to conclude that Buridan is considered as a 'philosophical materialist' since he believes that if we are to follow philosophical reasoning alone, apart from revealed truth, the materialism is to be preferred.