Still we have the word _infinite_, and we have _the notion_ which the word expresses. This, at least, is spared to us by Sir William Hamilton. He who says we have no such notion asks the question _how we have it?_ Here it may be asked, how have we, then, the word infinite? How have we the notion which this word expresses? The answer to this question is contained in the distinction of positive and negative thought. We have a positive concept of a thing when we think of it by the qualities of which it is the complement. But as the attribution of qualities is an affirmation, as affirmation and negation are relatives, and as relatives _are known only in and through each other_, we can not, therefore, have a _consciousness_ of the affirmation of any quality without having, at the same time, the _correlative consciousness_ of its negation. Now the one consciousness is a positive, the other consciousness is a negative notion; and as all language is the reflex of thought, the positive and negative notions are expressed by positive and negative names. Thus it is with the Infinite.[338] Now let us carefully scrutinize the above deliverance. We are told that "relatives are known only in and through each other;" that is, such relatives as _finite_ and _infinite_ are known necessarily in the same act of thought. The knowledge of one is as necessary as the knowledge of the other. We can not have a consciousness of the one without the correlative consciousness of the other. "For," says Hamilton, "a relation is, in truth, a thought, one and indivisible; and while the thinking a relation _necessarily involves the thought of its two terms,_, so it is, with equal necessity, itself involved in the thought of either." If, then, we are _conscious_ of the two terms of the relation in the same "one and indivisible" mental act--if we can not have "the consciousness of the one without the consciousness of the other"--if space and position, time and succession, substance and quality, infinite and finite, are given to us in pairs, then 'the _knowledge of one is as necessary as the knowledge of the other,_' and they must stand or fall together. The finite is known no more positively than the infinite; the infinite is known as positively as the finite. The one can not be taken and the other left. The infinite, discharged from all relation to the finite, could never come into apprehension; and the finite, discharged of all relation to the infinite, is incognizable too. "There can be no objection to call the one 'positive' and the other 'negative,' provided it be understood that _each_ is so with regard to the other, and that the relation is convertible; the finite, for instance, being the negative of the infinite, not less than the infinite of the finite."[339] [Footnote 338: _Logic,_ p. 73.] [Footnote 339: Martineau's "Essays," p. 237.]