But, since a text is supposed to make it sure that the sermon shall have in it one good sentence, let me take for my text a saying of the philosopher Kant, who, in one of his treatises, rests much upon the distinction to be made between logical and real or substantial opposition. According to him, a logical opposition is brought in view when one attribute of a certain thing is at once affirmed and denied. The statement of a body which should be at once stationary and in motion would imply such a contradiction, of which the result will be _nihil negativum irrepræsentabile_. A real or substantial opposition is found where two contradictory predicates are recognized as coexistent in the same subject. A body impelled in one direction by a given force, and in another by its opposite, is easily cogitable. One force neutralizes the other, but the result is something, viz., rest. Let us keep in mind this distinction between opposites which exclude each other, and opposites which can coexist, while we glance at the contradictions of all society, ancient as well as modern. How self-contradictory, in the first place, is the nature of man! How sociable he is! also how unsociable! We have among animals the gregarious and the solitary. But man is of all animals at once the most gregarious and the most solitary. This is the first and most universal contradiction, that of which you find at least the indication in every individual. But let us look for a moment at the contrasts which make one individual so unlike to another. We sometimes find it hard to believe the saying that God hath made of one blood all the nations of the earth. This in view of the contrast between savage and civilized nations, or between nations whose habits and beliefs differ one from the other. In the same race, in the same family also, we shall find the unlikeness which seems to set the bond of nature at defiance.