From the type thus outlined the mentality of the human race has departed so widely that some even of those who believe that our bodies have been derived from some simian stock (_e. g._ Wallace) hesitate to admit that our minds can have had a similar history. But as everywhere else in the animal kingdom mind and body constitute one organism, it is reasonable to consider whether the differentiation of the mind of man may not be understood to have taken place under the same conditions as those which determined the transformation of his body. What were these conditions?
(_a_) In the foregoing chapter I have collected a number of facts and arguments pointing to the probability that the chief cause of the evolution of the human Family was the adoption by some anthropoid (or allied form) of the life of the hunter in order to obtain animal food. That the change from a frugivorous to a carnivorous diet may itself have had some effect upon our temperament and activity is possible; but I lay no stress upon that. Most monkeys are almost exclusively frugivorous; the only Primate, except man, that depends a good deal upon animal food is, I believe, the crab-eating macaque (_Macacus cynomolgus_), of the Burmese and Malay littoral; yet monkeys are the most alert and active of animals; some of them are amongst the most courageous; anthropoids are amongst the most powerful. A carnivorous diet alone would not explain any changes in the shape and proportions of our trunk and limbs, nor the upright gait, nor the gregarious habit, nor the development of the brain, nor the invention of weapons, nor the use of fire, nor any of the mental and emotional characteristics that distinguish man from the other Primates; but all these things readily follow from our remote ancestor’s adoption of the life of the hunter.
Sociologists, surveying extant peoples, have usually distinguished four stages of culture, the hunting, pastoral, agricultural and manufacturing; and some have indicated what they suppose to have been a still earlier stage, the “collecting,” such as may be seen, _e. g._, amongst the Fuegians. But the collecting state is plainly degenerate, the resource of tribes fallen into distress; it cannot have been the first stage, because it implies no conditions that tend in any way to develop body or mind or society. That hunting came first is a true intuition: and, to understand the development of human nature, we need only refer the hunting-life back to the very origin of the human stock.[31]