Although the broad facts of history are known to us the causes that have contributed in the past to keep down some races while other peoples who were no better endowed or situated rose to the greatest heights of human effort cannot be stated with certainty. It is easy to cite the circumstances that are commonly conjectured as accounting for the origin and growth of civilisation, such as soil, climate and geographical position, but it is equally easy to point to times and places when and where great civilisations have arisen under conditions that have concurred elsewhere with miserable stagnation in rude barbarism. Climate is, perhaps, the factor which is most generally condescended upon as being the chief of the causes that contribute to that collective accomplishment which we call civilisation, but the connection between the two things is far from clear, indeed it seems to be often negatived by actual facts. Seeing, for instance, that the easy fruition of desire which is possible in tropical and sub-tropical latitudes does away with the idea of necessity as the mother of invention in those parts of the world it becomes difficult to see how tool-using man, who is generally supposed to have originated somewhere in the warm belts, came to take the first and the most difficult steps in the upward progress where there was so little, if any, incentive to that sustained effort and concentration of the mind which is required for the thinking out of the most difficult of all thoughts, the first principles of any art or craft. Why, we may well ask, should the primitive African have worried about cultivating the soil where edible roots and berries abounded? Why should he have bothered about making fire where there was no need of artificial warmth or for the cooking of food? Why should he have cudgeled his brains to fashion weapons and to contrive snares for the killing of game of which he was in no more need than his vegetarian cousins, the anthropoid apes? Why should there have been progress where the environment provided no stimuli therefore, in other words, why should primitive man have moved forward where indulgent nature allowed him to stand still? If we believe, with Darwin and other students, that our primitive ancestors emerged from somewhere within the warm zones, we cannot avoid the difficulty of reconciling that supposition with the theory that civilisation is in the first instance the result of a stimulating environment. If on the other hand, we surmise that _homo sapiens_ originated in the colder parts of the world we still have to account for the fact that his further progress was made not in those parts but in warmer latitudes where a genial climate afforded no apparent provocation for continued effort in the way of invention and general development.