By means of this explanation of the origin of the division of labour, Mr. Spencer proceeds to explain, in a way which would have astonished Adam Smith still more, other social phenomena of a kind which {33} seem wholly different. He proceeds to show us that though increased production of commodities was the chief direct result of the localisation of industries, certain by-products resulted from it also, whose effects were not less important. These by-products were roads. In the localisation of industries, he says, we have the true origin of road-making. The fact of industries being widely separated in place, required a constant interchange of the various sorts of goods; and the carriage of these goods to and fro between the same points first produced tracks, such as those made by animals, then paths, and at last regular roads. But to facilitate the movement and interchange of goods is not the only, or the highest, though it may be the first, function of roads. Roads facilitate two things of a yet more interesting character—the movement of ideas and the centralisation of authority. They form, in fact, the great physical basis of civilised human government, and of the development of the human intellect. These examples of Mr. Spencer’s conclusions will be sufficient to show how he studies the phenomena of social progress in so far as they are the result of what he calls “_the external factors_”—climate, locality, and the character of the other races with which each race that is studied happens to have been brought in contact. Let us now turn to what he calls the “_internal factors_,” and consider the phenomena of progress which he explains by reference to these. He helps us here by providing us with a summary of his own, in which he calls the attention {34} of his readers to the most important of his own conclusions arrived at in preceding chapters as to this section of his subject. Having reminded us of how he started with the “_external factors_,” and how he had shown the ways—namely those we have just glanced at—in which they co-operated to produce civilisation, “_our attention_,” he proceeds, “_was then directed to the internal factors_”; and what he had to tell us, he says, about the internal factors was as follows: “_An account was first given of ‘Primitive Man—physical,’ showing that by stature, structure, strength . . . he was ill fitted for overcoming the difficulties in the way of advance. Then examination of ‘The Primitive Man—emotional’ led us to see that his imprudence and his explosiveness, restrained but little by sociality and the altruistic sentiments, rendered him unfit for co-operation. And then, in the chapter on ‘Primitive Man—intellectual,’ we saw that while adapted by its active and acute perceptions to the needs of a wild life, his type of mind was deficient in the faculties required for progress in knowledge._” Then, having referred to the long explanation given by him of the rise of man’s religious belief, Mr.