complex and general ideas, which imply all the same intellectual impossibilities of comparing, judging, distinguishing, &c. _i.e._ of perceiving a number of diversified relations, of connecting the MANY into the ONE, which are objected to the more deliberate and formal acts of understanding and reason. The mind, say they, can perceive but one idea at a time, that is, it may perceive a square or a triangle, but it cannot compare them together, or perceive their proportions, because to do this, it must attend to different ideas at once. Yet what is this individual idea of a square, for instance, but an idea of given lines, their direction, equality, connection, &c. all which must be combined together in the mind, before it can possibly form any idea of the object? Mr. Tooke says, the complexity is in the term. I should say, the individuality is in the term, that is, in the application of one name to a collective idea, which superficial reasoners, at once the slaves of idle paradox and vulgar prejudice, have therefore imagined to be one thing. The whole error of this system has, indeed, arisen from considering ideas themselves, or those particular objects, which are marked by a single name, or strike at once, and in a mass, upon the senses, as simple things. But there is no one of these particular ideas, as they are called, which is not an aggregate of many things, or that can subsist for a moment but in the understanding. By destroying the composition of ideas, all ideas as well as all combinations of ideas, would be completely and for ever banished from the mind; which would be left a mere _tabula rasa_, a blank, indeed, or would at all times strictly resemble what Mr. Locke describes it to be in its original state, ‘a dark closet with a little glimmering of light let in through the loop-holes of the senses.’ Writers, in general, who have maintained the existence of a distinct faculty besides the senses, have applied themselves to shew that, besides particular ideas or objects, it was necessary to admit the understanding to explain the perception of the relations between them. My purpose is to shew that the same perception of relation, the same understanding is implied in the very ideas or objects themselves. To have sensations is not to compare them, that is, sensation and understanding are not the same thing. To have ideas, it is necessary to compare our sensations, that is, ideas and understanding are the same thing.