These answers divide themselves into two classes, which, though invariably confused by those that give them, are in reality quite distinct and separable. Professor Huxley, one of the most vigorous of our positive thinkers, shall help us to understand these. He is going to tell us, let us remember, about the '_highest good_'--the happiness, in other words, that we have just been discussing--the secret of our life's worth, and the test of all our conduct. This happiness he divides into two kinds.[8] He says that there are two things that we may mean when we speak about it. We may mean the happiness of a society of men, or we may mean the happiness of the members of that society. And when we speak of morality, we may mean two things also; and these two things must be kept distinct. We may mean what Professor Huxley calls '_social morality_,' and of this the test and object is the happiness of societies; or we may mean what he calls '_personal morality_,' and of this the test and object is the happiness of individuals. And the answers which our positive moralists make to us divide themselves into two classes, according to the sort of happiness they refer to. It is before all things important that this division be understood, and be kept quite clear in our minds, if we would see honestly what our positive modern systems amount to. For what makes them at present so very hard to deal with, is the fact that their exponents are perpetually perplexing themselves between these two classes of answers, first giving one, and then the other, and imagining that, by a kind of confusion of substance, they can both afford solutions of the same questions. Thus they continually speak of life as though its crowning achievement were some kind of personal happiness; and then being asked to explain the nature and basis of this, they at once shift their ground, and talk to us of the laws and conditions of social happiness. Professor Huxley will again supply us with a very excellent example. He starts with the thesis that _both_ sorts of morality are strong enough to hold their own, without supernatural aid; and when we look to see on what ground he holds they are, we find it to consist in the following explanation that _one_ is. '_Given_,' he says, '_a society of human beings under certain circumstances, and the question whether a particular action on the part of one of its members will tend to increase the general happiness or not, is a question of natural knowledge, and as such is a perfectly legitimate subject of scientific inquiry.... If it can be shown by observation or experiment, that theft, murder, and adultery do not tend to diminish the happiness of society, then, in the absence of any but natural knowledge, they are not social immoralities._'