The book "Theory of Forms: The Construction of Plato and Aristotle’s Criticism" focuses on two main aspects, construction and criticism. The constriction of Forms theory is the basis on which Plato built all of his philosophy and which influenced all forms of ideas philosophy that emerged after Plato. The research topic was completed by adding Aristotle's critique of the theory of Forms in order to put a clear picture in front of the reader, which was presented by Plato himself and Aristotle's criticism of this theory. Therefore, the book consists four chapters, the first chapter covers the following topics; The philosophical roots of Plato's theory of Forms, The numbers in the Pythagorean school, The Heraclitus' idea o...