1632-1704. English philosopher. He was the first major British empiricist, conceiving his role as a philosopher as an “underlabourer” to the “natural philosophy” of the [[Royal Society]]. In An Essay Concerning Human Understanding (1690), Locke rejected the innate ideas of the [[Cambridge Platonists]]* and Descartes* and claimed that the mind is a tabula rasa; all knowledge is the product of ideas, which are in turn derived either from sense-experience or self-awareness. Knowledge of the external world is the product of the ideas of the qualities of things. Some of these qualities (“primary qualities” such as “solidity, extension, figure, motion or rest, and number”) are in the world; others (“secondary qualities” such as sounds and colors), are in the perceiver. Primary qualities inhere in in- principle unknowable substances. Qualities must have substances, but it is impossible to say what these substances are. This doctrine of substance, together with the unclarity of Locke's central notion “idea,” is damaging. In his writings, “idea” stands both for a quality of mind and for a quality of the external world. If the former, then (as Berkeley* showed) Locke is committed to a version of idealism or, at best, to the existence of a world forever veiled in the unknown. If the latter, Locke is committed to a naïve realism.
In religion Locke is known chiefly as the opponent of “enthusiasm” (in the Essay) and as the proponent of an undogmatic rationalism (in The Reasonableness of Christianity, 1695). These views paved the way for the Deism of the following century. Locke denied the deistic implications of his remarks on religion in the Essay, while in controversy with [[Edward Stillingfleet]],* bishop of Worcester, but at the cost of some loss of consistency. It is undeniable that Deists such as Toland* appealed to Locke's “new way of ideas.”
In his Second Treatise of Government (1690), Locke argued that a civil society, with true rights and liberties for its members, is produced out of a “state of nature” by means of a “contract” between participating individuals. He is noteworthy as an advocate of toleration, though this did not extend to Roman Catholics.