The philosophy of Scottish school of common sense WF-FI-123-WMAN-KU24

The work of Thomas Reid, the founder of the Scottish School of Common Sense, was a response to the so-called "new philosophy" that dominated the second half of the 18th century. This philosophy was "new" in relation to medieval systems, as it emerged from the 17th-century scientific revolution and based its inquiries on the discoveries of specialized sciences, primarily physics and the corpuscular theory of nature.

Reid himself did not reject the achievements of contemporary science; he admired Newton’s work and believed that valuable philosophy could only be built by employing methods used in the natural sciences. He had in mind, above all, the philosophy of the mind. However, before attempting to construct such a philosophy, he first undertook a critique of existing systems. His analysis led him to conclude that all these systems were based on the same erroneous epistemological assumption.

Reid referred to this assumption, and the philosophical systems built upon it, as the "theory of ideas." He used this term to describe the claim that the external world can only be known through variously conceived intermediaries (ideas), which were considered the direct object of cognition. According to Reid, accepting this premise ultimately leads to skepticism regarding the existence of the so-called external world, other minds, or even our own minds—leaving only ideas as the sole existing entities.

The antidote to overcoming skepticism and false philosophy, according to Reid, lies in empiricism and the principles of common sense. These principles are innate aspects of our constitution, serving as the source of our concepts and beliefs concerning the operations of our own minds, the minds of others, the qualities of external objects, and the laws of nature.