odern philoso- phy, understanding by this term that which has been influenced by the rise of the newer natural science, has contained within itself an inner division. It has tried to combine acceptance of the conclusions of scientific inquiry as to the natural world with acceptance of doctrines about the nature of mind and knowledge which originated before there was such athing as systematic experimental inquiry. Between the two there is an inherent incompatibility. Hence the best efforts of philosophy have been constantly frustrated by artificiality and by contro- versial conflicts.