Perhaps no word in philosophy has been responsible for more confusion than the word idea. In Plato what in logic is called an uni versal, that is the common nature which thought recognizes in different particular things. Nowadays it sometimes means an opinion, sometimes mental images and sometimes it ap pears merely as an element in a paraphrasis as in °have an idea of.° Some of the greatest names in European philosophy are associated with the discussion of the question of innate ideas. Besides those already mentioned are Newton, Clark, Male branche, Lord Shaftesbury, Hobbes, Locke, Hume, Leibnitz, Cousin and Kant. What the followers of Cousin term universal, necessary and absolute, those of Descartes designate as innate ideas. The difference between the phi losophers is more verbal than real. Hobbes, indeed, in his zeal against Descartes, appears to have been not conscious of the fact that his conception of time as the mere of before and after notion,'" along with the rea son he gave for so saying, makes him approach more nearly the adherents of inborn ideas than even his opponent Descartes. In this respect
the late Herbert Spencer, who seems puzzled by his very natural possession of abstract ideas approaches Hobbes very nearly. At bottom, however, no essential difference between the real sentiments of the more important dispu tants, as Locke and Descartes existed at all. Modern psychology has set the question at rest. The genesis of ideas is as follows: A sensory experience, with many other impres sions like it, is realized in consciousness, and a sentient being has a sensation. Sensations become, in time, percepts. Many percepts of the same kind become concepts or ideas. From concepts abstractions are drawn. And among such abstractions our ideas of freedom, immor tality, and even of God, are to be numbered. In other words, enihil est in intellect* quod non fuerit in sensu,— there is nought in knowl edge, that was not born of the spirit.*