Convertible, however, rather than already converted. When we consider how deeply embedded in customs of thought and action the classic philosophy came to be and how congenial it is to man's more spontaneous beliefs, the throes that attended its birth are not to be wondered at. We should rather wonder that a view so upsetting, so undermining, made its way without more persecutions, martyrdoms and disturbances. It certainly is not surprising that its complete and consistent formulation in philosophy has been long delayed. The main efforts of thinkers were inevitably directed to minimizing the shock of change, easing the strains of transition, mediating and reconciling. When we look back upon almost all of the thinkers of the seventeenth and eighteenth centuries, upon all excepting those who were avowedly sceptical and revolutionary, what strikes us is the amount of traditional subject-matter and method that is to be found even among those who were regarded as most advanced. Men cannot easily throw off their old habits of thinking, and never can throw off all of them at once. In developing, teaching and receiving new ideas we are compelled to use some of the old ones as tools of understanding and communication. Only piecemeal, step-by-step, could the full import of the new science be grasped. Roughly speaking, the seventeenth century witnessed its application in astronomy and general cosmology; the eighteenth century in physics and chemistry; the nineteenth century undertook an application in geology and the biological sciences. It was said that it has now become extremely difficult to recover the view of the world which universally obtained in Europe till the seventeenth century. Yet after all we need only recur to the science of plants and animals as it was before Darwin and to the ideas which even now are dominant in moral and political matters to find the older order of conceptions in full possession of the popular mind. Until the dogma of fixed unchangeable types and species, of arrangement in classes of higher and lower, of subordination of the transitory individual to the universal or kind had been shaken in its hold upon the science of life, it was impossible that the new ideas and method should be made at home in social and moral life. Does it not seem to be the intellectual task of the twentieth century to take this last step? When this step is taken the circle of scientific development will be rounded out and the reconstruction of philosophy be made an accomplished fact. CHAPTER IV CHANGED CONCEPTIONS OF EXPERIENCE AND REASON