<epistemology, metaphysics, empiricism> what we experience directly -- such as shapes, colors, and smells - in perceptual experience. Roughly identifiable, with Locke's "simple ideas" and Hume's "impressions". For Kant these are the "matter" of perception for which time and space are the a priori forms. Among contemporary philosophers, sensations (or their distinctive "felt" properties) are commonly called "qualia." Among the {presumed contents of the mind, sensations (being concrete & particular) stand in contrast to (abstract & general, or universal]) {concepts: compare the experience of seeing red to the idea of redness.
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