Rationalism

Rationalism is the epistemological view that "regards reason as the chief source and test of knowledge" or "any view appealing to reason as a source of knowledge or justification". More formally, rationalism is defined as a methodology or a theory "in which the criterion of truth is not sensory but intellectual and deductive".

Ancient Rationalism
Ancient Rationalism refers to the philosophical tradition that emerged in ancient Greece, with notable thinkers such as Parmenides, Zeno of Elea, and Plato. These philosophers emphasized the use of reason and rational thought to gain knowledge of the world, as opposed to relying on tradition, superstition, or revelation. They sought to understand the nature of reality through logical deduction and the use of concepts and ideas, rather than through sensory experience alone. The legacy of ancient rationalism can be seen in the development of Western philosophy and the continued influence of rationalist principles in contemporary thought.

Classical Rationalism
Classical Rationalism emerged as a philosophical movement in the 17th century, largely in response to the dominant scholasticism of the time. René Descartes is often regarded as the founder of modern rationalism, with his emphasis on the use of reason and deductive logic in the pursuit of knowledge. Rationalism gained further momentum through the works of Baruch Spinoza and Gottfried Leibniz. However, the rise of empiricism in the 18th century challenged the dominance of rationalism in philosophy, leading to a shift in focus towards empirical observation and experimentation as the primary means of acquiring knowledge.