Now Edwards has not pretended to say how a volition acts upon the external part of our being; if he had done so, he would have been justly obnoxious to the charge of presuming to know how a cause acts, in the proper sense of the word; but he has done no such thing. The connexion between cause and effect, in the proper sense of the terms, he has left enveloped in profound mystery. He has not presumed to say how an act, or cause, properly so called, produces its corresponding effect. He does not assume to know how a cause acts; but how what is sometimes called a cause really becomes such. The will may be called a cause, if you please; but, in reality, unless it acts, it is the cause of no effect; and even then, properly speaking, the act is the cause. He clearly saw that a will which lies still and does nothing, is the cause of no effect; and hence he stated the simple fact, that it must act in order to become a cause, or, which is the same thing, in order to produce an effect. And is not this perfectly self-evident? We do not know how the will acts, nor how its act produces a change in the external part of our being; but yet do we not certainly know, that a dormant will can do nothing, and that it must act in order to produce an effect. If this be to explain how a cause acts, I humbly conceive that we may do so with perfect propriety. Indeed, all that is assumed by Edwards, has been conceded to him by most of his adversaries. Thus says Dr. West, as quoted by Edwards the younger, "No being can become a cause, i. e. an efficient, or that which produces an effect, but by first operating, acting, or energizing." Here we are told, not how a cause acts, but how the mind becomes a cause, or the author of effects. This is all that Edwards takes for granted; and, for aught that I can see, he has done so with perfect propriety. The same thing is conceded by Dr. Reid. "The change," says he, "whether it be of thought, of will, or of motion, is the effect. Active power, therefore, is a quality in the cause, which enables it to produce the effect. And the exertion of that active power in producing the effect, is called action, agency, efficiency. In order to the production of any effect, there must be in the cause, not only power, _but the exertion of that power_."--Essays on the Active Powers, p. 259. Here it is declared by Dr. Reid, that active power or the will must act, in order to produce an effect, whether the effect be in the mind itself, or out of the mind, whether it be "of thought, of will, or of motion." This is all that Edwards assumes as the basis of his argument.