In discussing progress I shall therefore with right employ those moral conceptions which I have already defined. I shall regard as good whatever fulfils interests, and as morally good whatever fulfils all interests affected to the maximum degree. Especial importance now attaches to the principle which I have phrased the _quantitative basis of preference_. Since progress involves the change from good to better, it implies an increment of value. The later age is judged to be _as good and better_. I can see no way of verifying such a proposition unless it be possible to find in the greater good both the lesser good and also something added to it and likewise accounted good. In other words, progress involves measurement of value, and this involves some _unit of value_ which is common to the terms compared. The method must be in the last analysis that of superimposition. Bagehot virtually employs this method in the chapter of his _Physics and Politics_, which he entitles "Verifiable Progress Politically Considered." Let me quote, for example, his comparison of the Englishman with the primitive Australian. If we omit the higher but disputed topics of morals and religion, we shall find, I think, that the plainer {128} and agreed-on superiorities of the Englishmen are these: first, that they have a greater command over the powers of nature upon the whole. Though they may fall short of individual Australians in certain feats of petty skill, though they may not throw the boomerang as well, or light a fire with earthsticks as well, yet on the whole twenty Englishmen with their implements and skill can change the material world immeasurably more than twenty Australians and their machines. Secondly, that this power is not external only; it is also internal. The English not only possess better machines for moving nature, but are themselves better machines. Mr. Babbage taught us years ago that one great use of machinery was not to augment the force of man, but to register and regulate the power of man; and this in a thousand ways civilized man can do, and is ready to do, better and more precisely than the barbarian. Thirdly, civilized man has not only greater powers over nature, but knows better how to use them, and by better I here mean better for the health and comfort of his present body and mind. He can lay up for old age, which a savage having no durable means of sustenance cannot; he is ready to lay up because he can distinctly foresee the future, which the vague-minded savage cannot.[2] It will be observed that in each case the superiority of the Englishmen lies in the fact that they _beat the Australians at their own game_. Australians are as much interested as Englishmen in obtaining command over nature, in organizing their own powers, and in securing health and comfort. The Englishmen, however, can fulfil these interests not only up to but also beyond {129} the point which marks the limit of the Australians' attainment.