 Reid’s moral philosophy, according to the gloss offered thus far, is an agency-centered intuitionist position, which also blends together both rationalist and sentimentalist influences. Given its synthetic character, it is natural to ask how best to enter into Reid’s thought. A promising avenue is to note a pattern of thought present in Reid’s work. In his work in epistemology and philosophy of mind, which is found primarily in An Inquiry into the Human Mind (IHM) and Essays on the Intellectual Powers of Man (EIP), Reid frames his project as a response to a general position that he calls the Way of Ideas. This position, which Reid says unites philosophers as diverse as Aristotle, Locke, Berkeley, and Hume, holds that we are never acquainted with the external world but only with “images” or sense data in the mind. What Reid says positively about our perception of the external world is couched as a response to this view. Although it is rarely noted, Reid’s work in ethics in Essays on the Active Powers of Man (EAP) is also framed as a response to a general position, which he claims is adopted by philosophers as diverse as Spinoza, Leibniz, and Hume. This position Reid ordinarily calls the System of Necessity. Reid’s own positive views about the nature of agency and the moral domain are best viewed as a response to the System of Necessity. Let us, then, enter Reid’s moral philosophy by having before us the rudiments of the System of Necessity.