How did Aristotle’s approach to reason differ from Plato’s theory of forms?

The fundamental difference between Aristotle and Plato regarding reason and the nature of reality lies in their treatment of forms.

For Plato, Forms are perfect, eternal, and immutable archetypes that exist in a suprasensible realm entirely independent of space and time. Because the sensible world is merely a collection of imperfect copies of these Forms, Plato argued that true reality is accessible only through reason and dialectic, rather than through sense experience.123

Aristotle, while acknowledging the importance of reason, rejected the existence of an independent realm of Forms. Instead, he proposed that forms are immanent—they exist only as they are embodied in matter within the physical world. For Aristotle, the work of reason was to explain these particular facts by bringing them under general principles through syllogistic logic. While Plato pointed toward an abstract, otherworldly reality, Aristotle focused on the empirical, practical, and "this-worldly" study of nature, viewing form as the internal structure or purpose that defines a thing's essence.143