Utilitarian ethics receive unexpected help from natural science. Biology declares itself able to explain by reference to its origin the devotion to others which thinkers had decided to accept as inherent in man by the side of the egoistic, but not further derivable from it. The unegoistic, so it teaches, does as a matter of fact grow out of the egoistic, only it does not issue from it afresh on every occasion as a result of conscious reflexion by the individual. The change has taken place in the species by a long and slow process, and is now revealed as an acquired faculty. The conviction that the welfare of the individual is best secured if the whole body of individuals is also active in promoting the common good has been established by experience in the struggle for existence. Action on this principle has thus become a characteristic of individuals which develops more and more in the course of generations. We possess this devotion to others as descendants of herds which maintained themselves in the struggle for existence while others succumbed in it, because the social impulses were developed in them the most strongly and the most universally. [pg 154] This thought is developed by Charles Darwin (1869-1882)_(_55_)_ in his _Descent of Man_, and by Herbert Spencer (1820-1903)_(_56_)_ in his _Principles of Ethics_. Each of these thinkers refers to the other. Altruism is therefore now regarded as something natural and at the same time as something which has come into existence through reflexion, and the relation subsisting between it and egoism as having admittedly become rational. On this judgement is founded at the same time the conviction that the co-operation of these two impulses, as it developed in the past, will allow itself also to be perfected in the future. More and more will these two impulses show clearly their mutual dependence on each other. From sporadic altruism, developing in the animal kingdom for the production and maintenance of new generations, we have advanced to a settled altruism which serves the maintenance of the family and society. To bring this to completion must now be our aim. We shall succeed if the compromise between egoism and altruism continues to grow better adjusted and more purposive. We must advance to the view which at first seems to be a paradox that (to use Spencer’s language) the general prosperity can be reached mainly through a corresponding struggle of all individuals for their own prosperity and that of individuals, on the other hand, partly through their struggle for the general prosperity. Comte’s _Physiology of Society_ is thus given a foundation in natural science by Darwin and Spencer.