section_path: Natural philosophy/Psychology/Soul
section_name: Soul
paragraph_text: Soul
  
  Aristotle's psychology, given in his treatise On the Soul (peri psychēs), posits three kinds of soul ("psyches"): the vegetative soul, the sensitive soul, and the rational soul. Humans have all three. The vegetative soul is concerned with growth and nourishment. The sensitive soul experiences sensations and movement. The unique part of the human, rational soul is its ability to receive forms of other things and to compare them using the nous (intellect) and logos (reason).
  
  For Aristotle, the soul is the form of a living being. Because all beings are composites of form and matter, the form of living beings is that which endows them with what is specific to living beings, e.g. the ability to initiate movement (or in the case of plants, growth and transformations, which Aristotle considers types of movement). In contrast to earlier philosophers, but in accordance with the Egyptians, he placed the rational soul in the heart, rather than the brain. Notable is Aristotle's division of sensation and thought, which generally differed from the concepts of previous philosophers, with the exception of Alcmaeon.
  
  In On the Soul, Aristotle famously criticizes Plato's theory of the soul and develops his own in response. The first criticism is against Plato's view of the soul in the Timaeus that the soul takes up space and is able to come into physical contact with bodies. 20th-century scholarship overwhelmingly opposed Aristotle's interpretation of Plato and maintained that he had misunderstood him. Today's scholars have tended to re-assess Aristotle's interpretation and been more positive about it. Aristotle's other criticism is that Plato's view of reincarnation entails that it is possible for a soul and its body to be mis-matched; in principle, Aristotle alleges, any soul can go with any body, according to Plato's theory. Aristotle's claim that the soul is the form of a living being eliminates that possibility and thus rules out reincarnation.