Chapter I. is on the origin of our Ideas of Right and Wrong. The actions of moral agents, he says, give rise in us to three different perceptions: 1st, Right and Wrong; 2nd, Beauty and Deformity; 3rd, Good or Ill Desert. It is the first of these perceptions that he proposes mainly to consider. He commences by quoting Hutcheson's doctrine of a Moral Sense, which he describes as an _implanted_ and _arbitrary_ principle, imparting a relish or disrelish for actions, like the sensibilities of the various senses. On this doctrine, he remarks, the Creator might have annexed the same sentiments to the opposite actions. Other schemes of morality, such as Self-love, Positive Laws and Compacts, the Will of the Deity, he dismisses as not meeting the true question. The question, as conceived by him, is, 'What is the power within us that perceives the distinctions of Right and Wrong?' The answer is, The UNDERSTANDING. To establish this position, he enters into an enquiry into the distinct provinces of Sense and of Understanding in the origin of our ideas. It is plain, he says, that what judges concerning the perceptions of the senses, and contradicts their decisions, cannot itself be sense, but must be some nobler faculty. Likewise, the power that views and compares the objects of all the senses cannot be sense. Sense is a mere capacity of being passively impressed; it presents _particular_ forms to the mind, and is incapable of discovering general truths. It is the understanding that perceives order or proportion; variety and regularity; design, connexion, art, and power; aptitudes, dependence, correspondence, and adjustment of parts to a whole or to an end. He goes over our leading ideas in detail, to show that mere sense cannot furnish them. Thus, Solidity, or Impenetrability, needs an exertion of reason; we must compare instances to know that two atoms of matter cannot occupy the same space. _Vis Inerticæ_ is a perception of the reason. So Substance, Duration, Space, Necessary Existence, Power, and Causation involve the understanding. Likewise, that all Abstract Ideas whatsoever require the understanding is superfluously proved. The author wonders, therefore, that his position in this matter should not have been sooner arrived at. The tracing of Agreement and of Disagreement, which are functions of the Understanding, is really the source of simple ideas. Thus, Equality is a simple idea originating in this source; so are Proportion, Identity and Diversity, Existence, Cause and Effect, Power, Possibility and Impossibility; and (as he means ultimately to show) Right and Wrong.