These unremitting changes and adaptations that go forward in the scheme of institutions, legal and customary, unremittingly induce new habits of work and of thought in the community, and so they continually instil new principles of conduct; with the outcome that the same range of instinctive dispositions innate in the population will work out to a different effect as regards the demands of race survival. To all appearance, what counts first in this connection toward the selective survival of the several European racial stocks is their relative fitness to meet the material requirements of life,--their economic fitness to live under the new cultural limitations and with the new training which this altered cultural situation gives. But the fortunes of the Western civilisation as a cultural scheme, apart from the biological survival or success of any given racial constituent in the Western peoples, is likewise bound up with the viability of European mankind under these institutional changes, and dependent on the spiritual fitness of inherited human nature successfully and enduringly to carry on the altered scheme of life so imposed on these peoples by the growth of their own culture. Such limitations imposed on cultural growth by native proclivities ill suited to civilised life are sufficiently visible in several directions and in all the nations of Christendom. * * * * * What is known of heredity goes to say that the various racial types of man are stable; so that during the life-history of any given racial stock, it is held, no heritable modification of its typical make-up, whether spiritual or physical, is to be looked for. The typical human endowment of instincts, as well as the typical make-up of the race in the physical respect, has according to this current view been transmitted intact from the beginning of humanity, that is to say from whatever point in the mutational development of the race it is seen fit to date humanity,--except so far as subsequent mutations have given rise to new racial stocks, to and by which this human endowment of native proclivities has been transmitted in a typically modified form. On the other hand the habitual elements of human life change unremittingly and cumulatively, resulting in a continued proliferous growth of institutions. Changes in the institutional structure are continually taking place in response to the altered discipline of life under changing cultural conditions, but human nature remains specifically the same.