Reason is the discovery of truth or falsehood. Truth or falsehood consists in an agreement or disagreement either to the _real_ relations of ideas, or to _real_ existence and matter of fact. Whatever therefore is not susceptible of this agreement or disagreement, is incapable of being true or false, and can never be an object of our reason. Now, 'tis evident our passions, volitions, and actions, are not susceptible of any such agreement or disagreement; being original facts and realities, complete in themselves, and implying no reference to other passions, volitions, and actions. 'Tis impossible, therefore, they can be pronounced either true or false, and be either contrary or conformable to reason. This argument is of double advantage to our present purpose. For it proves _directly_, that actions do not derive their merit from a conformity to reason, nor their blame from a contrariety to it; and it proves the same truth more _indirectly_, by showing us, that as reason can never immediately prevent or produce any action by contradicting or approving of it, it cannot be the source of moral good and evil, which are found to have that influence. Actions may be laudable or blameable; but they cannot be reasonable or unreasonable: laudable or blameable, therefore, are not the same with reasonable or unreasonable. The merit and demerit of actions frequently contradict, and sometimes control our natural propensities. But reason has no such influence. Moral distinctions, therefore, are not the offspring of reason. Reason is wholly inactive, and can never be the source of so active a principle as conscience, or a sense of morals. But perhaps it may be said, that though no will or action can be immediately contradictory to reason, yet we may find such a contradiction in some of the attendants of the action, that is, in its causes or effects. The action may cause a judgment, or may be _obliquely_ caused by one, when the judgment concurs with a passion; and by an abusive way of speaking, which philosophy will scarce allow of, the same contrariety may, upon that account, be ascribed to the action. How far this truth or falsehood may be the source of morals, 'twill now be proper to consider.