Were a man to abstract from every thing which he knows or has seen, he would be altogether incapable, merely from his own ideas, to determine what kind of scene the universe must be, or to give the preference to one state or situation of things above another. For as nothing which he clearly conceives, could be esteemed impossible or implying a contradiction, every chimera of his fancy would be upon an equal footing; nor could he assign any just reason, why he adheres to one idea or system, and rejects the others, which are equally possible. Again; after he opens his eyes, and contemplates the world, as it really is, it would be impossible for him, at first, to assign the cause of any one event; much less, of the whole of things or of the universe. He might set his Fancy a rambling; and she might bring him in an infinite variety of reports and representations. These would all be possible; but being all equally possible, he would never, of himself, give a satisfactory account for his preferring one of them to the rest. Experience alone can point out to him the true cause of any phenomenon.
To body we ascribe various properties, but not operations, properly so called; it is extended, divisible, movable, inert; it continues in any state in which it is put; every change of its state is the effect of some force impressed upon it, and is exactly proportional to the force impressed, and in the precise direction of that force. These are the general properties of matter, and these are not operations; on the contrary, they all imply its being a dead, inactive thing, which moves only as it is moved, and acts only by being acted upon. But the mind is, from its very nature, a living and active being. Every thing we know of it implies life and active energy; and the reason why all its modes of thinking are called its operations is, that in all, or in most of them, it is not merely passive, as body is, but is really and properly active. In all ages, and in all languages, ancient and modern, the various modes of thinking have been expressed by words of active signification, such as seeing, hearing, reasoning, willing, and the like. It seems, therefore, to be the natural judgment of mankind, that the mind is active in its various ways of thinking; and for this reason they are called its operations, and are expressed by active verbs. It may be made a question, What regard is to be paid to this natural judgment? May it not be a vulgar error? Philosophers who think so have, no doubt, a right to be heard. But until it is proved that the mind is not active in thinking, but merely passive, the common language with regard to its operations ought to be used, and ought not to give place to a phraseology invented by philosophers, which implies its being merely passive.