(384-323 B.C.E.)
Greek Philosopher

Portuguese Version



  • Probably studied in Plato’s Academy and was Plato’s student


  • 347-344 B.C.E., teacher, writer, scientific collector at Assus (Asia Minor)
  • 344-342 B.C.E., same at Mitylene (Lesbos)
  • 342-336 B.C.E., tutor of Alexander the Great at Pella (Macedonia)
  • 335-323 B.C.E., in Athens, established his school, the Lyceum, completed most of his psychological writings

Ideas and Contributions

Aristotle is often regarded as the father of psychology, and his book, De Anima (On the Soul), the first book on psychology. He was concerned with the connection between the psychological processes and the underlying physiological phenomenon. Many believe he contributed more to prescience psychology than any other person, both qualitatively and quantitatively. Although Aristotle attended Plato’s Academy, he became convinced of the need for empirical observations and criticized many of Plato’s philosophies. Plato and Aristotle “represent a basic divergence in the way man and the world may be viewed, a modern parallel being the difference between the clinical and the experimental psychologist. (Zusne, p. 8)”

Aristotle postulates that the body and the mind exist as facets of the same being, with the mind being simply one of the body’s functions. He suggests that intellect consists of two parts: something similar to matter (passive intellect) and something similar to form (active intellect). Aristotle says that intellect “‘is separable, impassible, unmixed, since it is in its essential nature activity. . . . When intellect is set free from its present conditions, it appears as just what it is and nothing more: it alone is immortal and eternal . . . and without it nothing thinks (Britannica Online, “Physiological Psychology”).”

Aristotle described the psyche as a substance able to receive knowledge. Knowledge is obtained through the psyche’s capability of intelligence, although the five senses are also necessary to obtain knowledge. “As Aristotle describes the process, the sense receives ‘the form of sensible objects without the matter, just as the wax receives the impression of the signet-ring without the iron or the gold.’ (Britannica Online, “Physiological Psychology”).” Sensitivity is stimulated by phenomenon in the environment, and memory is the persistence of sense impressions. He maintained that mental activities were primarily biological, and that the psyche was the “form” part of intellect. Aristotle insisted that the body and the psyche form a unity. This idea is known as hylomorphic.

Aristotle believed that thinking requires the use of images. While some animals can imagine, only man thinks. Knowing (nous) differs from thinking in that it is an active, creative process leading to the recognition of universals; it is akin to intuition, it does not cause movement, and it is independent of the other functions of the psyche. (Zusne, pp. 8-9)

Thomas Aquinas based many of his ideas on those of Aristotle, metaphysically interpreting them to make them fit his Christian theological framework. Thomistic psychology is still taught in Catholic schools today.

Publications (largely in the form of lecture notes made by his students)

  • Organum (tretises on logic)
  • Physics; Metaphysics; Ploitics; De Poetica; and Rhetoric
  • Nicomachean Ethics and Eudemian Ethics
  • De Anima, Parva Naturalia (includes “On the Senses and the Sensible,” “On Memory and Reminiscence,” “On Sleep and Sleeplessness,” and “On Dreams)
  • “On Youth and Old Age, On Life and Death”


Britannica Online. (1994-1997). The history of epistemology: Ancient philosophy. Retrieved 1997 from http://www.britannica.com

Zuzne, L. (Ed.) (1957). Names in the history of psychology. New York: John Wiley & Sons.

Image courtesy of The National Library of Medicine