_The motive_ is the cause of choice, and is complex. It lies in the nature and susceptibilities of the will, and in the nature and circumstances Of the object chosen. IX. The will and reason may be opposed; that is, what reason commands may seem disagreeable to the will, and of course reason cannot be obeyed. Reason can be obeyed only when her commands produce the sense of the most agreeable. X. The terms necessity, and freedom or liberty are opposed in reference to will. Freedom or liberty is the attribute of the man--the human soul. The man is free when his volitions or choices are unimpeded,--when, upon choosing to walk, he walks, &c. The man is not free, or is under necessity, when his volitions or choices are impeded,--when, upon choosing to walk, he finds his legs bound or paralysed, &c. Then it is _impossible_ for him to walk,--then he has _no liberty_ to walk,--then he is under a _necessity_ of remaining in one place. Necessity in any other use is _metaphysical_ or _philosophical_ necessity, and is applied out of the sphere of the will: as the necessity of truth, the necessity of being,--the necessary connexion of cause and effect. Hence, The _connexion_ between volitions or choices, or the sense of the most agreeable with the motive or cause, is _necessary_ with a philosophical necessity. The necessity of volitions in reference to motives is also called _moral_ necessity. This term _moral_ is given, not in reference to the nature of the connexion, but in reference to the _terms_ connected. Volitions belonging to responsible and moral beings are thus distinguished from those phenomena which we commonly call _natural_. XI. An agent is that which produces effects. A _natural_ agent is that which produces effects without volition. A _moral_ agent is one producing effects by volitions, accompanied with an intellectual perception of the volitions and their effects, as right or wrong, and a sense of desert, or of praiseworthiness, or blameworthiness, on account of the volitions and their effects. _Brutes_ or irresponsible beings are agents that have volitions, but have no reason to perceive right and wrong, and consequently have no sense of desert; and as they cannot perceive right and wrong, they cannot be made the subjects of moral appeals and inducements. XII. Moral responsibility arises first, from the possession of reason; secondly, from the capacity of choice; thirdly, from natural ability. Natural ability exists when the effect or act commanded to be accomplished has an established connexion with volition or choice. Thus we say a man has natural ability to walk, because if he chooses to walk, he walks. Natural ability differs from freedom only in this:--The first refers to an established connexion between volitions and effects. The second refers to an absence of all impediment, or of all resisting forces from between volitions and effects.