The individual hunter, if he failed to show the grade of ability necessary to supply his wants, promptly died of his own inferiority, but man, in social relation, is maintained by the collective effort, prospering or suffering with his society, and his pooling of abilities is so far-reaching and hopelessly intermixed that it is impossible to pick out the consequences of one man’s action and pile them neatly on his own head. Naturally, selection acts on the society rather than the man, and must needs act slowly and with an appearance of injustice. Incipient errors are not met by the sharp reproof of individual consequence, and wide ranges of eccentricity are possible, so that they do not touch those basic economic processes of society on which all our lives rest. Gross mistakes in agriculture would be soon punished by the extinction of the mistaken society, or errors in mechanics, in navigation, in any part of our work which deals with the primal necessities of life, but errors in astronomy, in religion, or education do not result in such immediate destruction. Thus the human intellect on the lower stages shows a certain solid average ability, built up by natural selection acting on societies as it acts on individuals, but the human intellect in its higher grades is painfully irregular and defective, making our higher social manifestations as questionable, uncertain, and often mischievous as our lower ones are clearly good. Man has stayed alive because he knew enough to plough and sow, to kill wolves and steer a ship, but in later social development he has been as open to destruction as any poor beast below him. In the long lesson of history we may see him again and again killed down to the level of his intelligence. Nations have been conquered, civilisations destroyed, kings decapitated, but the peasant survived. The problems we have really solved do not have to be done over again; the downfall of past societies is but the wiping off the slate of a mass of elaborate failures. “Rule it all out down to that first line and begin again!” says the teacher. We are quite clever at simple examples in units, but very weak on fractions. We could see how one man affected another in the short radius of a limited early group, but the long-range effects of our widening interhuman activities have been beyond us, and we are slowly working out in heavy centuries those problems of liberty and justice, of honesty and love, the mastery of which is as essential to our further progress as was the early mastery of metallurgy and mechanics. A mistake in short and simple addition is easily seen, but as the examples grow more complex the errors are more difficult to trace.