<gnoseology, philosophy of science, logic> features of ideas considered as mental entities, without regard for their external relation to objects they are supposed to represent. An idea is clear if its content is precise and detailed; otherwise, it is obscure. An idea is distinct if it can be distinguished from any other idea, confused if it cannot. (Although the two notions are formally distinct, they are commonly supposed to coincide, on the grounds that clarity is a necessary and sufficient condition for distinctness.) Descartes held that the clarity and distinctness of our ideas is a criterion for the truth of what we believe.
[A Dictionary of Philosophical Terms and Names]
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