An Essay Concerning Human Understanding

London: Thomas Tegg, 1825. Twenty-Fifth edition. Hardcover. g. Quarto. XVI, 568pp. Uncut. Original paper covered boards. Engraved frontispiece portrait of the author. An "Essay Concerning Human Understanding" is one of John Locke's two most famous works, the other being his "Second Treatise on Civil Government". First appearing in 1690, the essay concerns the foundation of human knowledge and understanding. He describes the mind at birth as a blank slate (tabula rasa, although he did not use those actual words) filled later through experience. The essay was one of the principal sources of empiricism in modern philosophy, and influenced many enlightenment philosophers, such as David Hume and Bishop Berkeley. Book II of the Essay sets out Locke's theory of ideas, including his distinction between passively acquired simple ideas, such as "red," "sweet," "round," etc., and actively built complex ideas, such as numbers, causes and effects, abstract ideas, ideas of substances, identity, and diversity. Locke also distinguishes between the truly existing primary qualities of bodies, like shape, motion and the arrangement of minute particles, and the secondary qualities that are "powers to produce various sensations in us" such as "red" and "sweet." These secondary qualities, Locke claims, are dependent on the primary qualities. He also offers a theory of personal identity, offering a largely psychological criterion. Book III is concerned with language, and Book IV with knowledge, including intuition, mathematics, moral philosophy, natural philosophy ("science"), faith, and opinion. This work contains a large folding chart being an analysis of Mr Locke's doctrine of ideas in his essay on human understanding. Some age wear on binding with spine missing and age-toning on covers. Previous owner's signature on free front endpaper. Sporadic foxing on endpapers and very first pages. Binding in overall poor, interior in near fine condition.