 Locke and Descartes both pursue a method in epistemology that brings with it the epistemological problem of objectivity. Both examine our knowledge by way of examining the ideas we encounter directly in our consciousness. This method comes to be called “the way of ideas”. Though neither for Locke nor for Descartes do all of our ideas represent their objects by way of resembling them (e.g., our idea of God does not represent God by virtue of resembling God), our alleged knowledge of our environment through the senses does depend largely on ideas that allegedly resemble external material objects. The way of ideas implies the epistemological problem of how we can know that these ideas do in fact resemble their objects. How can we be sure that these objects do not appear one way before the mind and exist in another way (or not at all) in reality outside the mind? George Berkeley, an empiricist philosopher influenced by John Locke, avoids the problem by asserting the metaphysics of idealism: the (apparently material) objects of perception are nothing but ideas before the mind. However, Berkeley’s idealism is less influential in, and characteristic of, the Enlightenment, than the opposing positions of materialism and Cartesian dualism. Thomas Reid, a prominent member of the Scottish Enlightenment, attacks the way of ideas and argues that the immediate objects of our (sense) perception are the common (material) objects in our environment, not ideas in our mind. Reid mounts his defense of naïve realism as a defense of common sense over against the doctrines of the philosophers. The defense of common sense, and the related idea that the results of philosophy ought to be of use to common people, are characteristic ideas of the Enlightenment, particularly pronounced in the Scottish Enlightenment.