from causes which are in essence identical, and which have called forth and developed all the faculties of beings endowed with the power of moving themselves. With that almost the last barrier between man and animal was torn down. Darwin did not follow up his discoveries any further, and yet they belong to the greatest and most fruitful of the human intellect, and enable us to develop a new critique of knowledge.
When we study the organic world it reveals to us one very striking peculiarity as compared with the inorganic; we find in it adaptation to end. All organised beings are constructed and endowed more or less with a view to an end. The end which they serve is, nevertheless, not one which lies outside of them. The world as a whole has no aim. The aim lies in the individuals themselves: its parts are so arranged and fitted out that they serve the individual, the whole. Purpose and division of labour arise together. The essence of the organism is the division of labour just as much as adaption to end. One is the condition of the other. The division of labour distinguishes the organism from inorganic individuals, for example, crystals. Even crystals are distinct individuals, with a distinct form; they grow when they find the necessary material for their formation, under the requisite conditions; but they are through and through symmetrical. On the other hand, the lowest organism is a vesicle, much less visible and less complicated than a crystal; but a vesicle whose external side is different, and has different functions from the inner.
That the division of labour should be that one which is suitable for the purpose, that is, one which is useful to the individual, that which renders his existence possible, or even ameliorates it, seems wonderful. But it would be still more wonderful if individuals maintained themselves and procreated with a division of labour which was not suitable for the purpose, which rendered their existence difficult or even impossible.
But what is the work which the organs of the organism have to accomplish? This work is the struggle for life, that is, not the struggle with other organisms
