We have in the first place the increase of the size of units, familiar to us already in lower forms. This, however, is tending to a limit, which will be attained when the present competition of sovereign states has been replaced (as, if we can read the future from the past, it inevitably will be) by some form of federation covering the globe. We find an immense increase of control over environment--a theme so hackneyed as to need no labouring. We find an almost equally striking, if less spectacular, increase in independence. Man becomes less and less at the mercy of the forces of nature and of other organisms, attains much more to self-regulation. This has depended upon increased efficiency of “organs”--here the extra-organismal organs we call tools and machines; and upon increased rapidity and certainty of communication both within and between units. There has been an almost overwhelming increase (displaying too not a uniform but an accelerated motion) of knowledge, of the possibilities of acquiring new knowledge, and of what may be called the “group-memory”--the power of storing and rendering knowledge available, and this in its turn brings about a huge increase in the size of the environment with which man either physically or mentally comes into contact. As regards increase of harmony or co-ordination, human communities have advanced but little, although in the increase of powers of communication there has been laid the foundation for such possibility. That this lack of progress is partly due to the extreme rapidity of change in type of unit and of the units’ increase in size, is not doubtful; a further ground for it, however, is to be found in the fact that human societies present a new biological problem, in so much as it is impossible, man being what he is, to solve the relationship of individual and community, of smaller and larger unit, in the simple way in which it has always been solved before--by specialization and subordination of the individuals.[16] The early development of codes of law, codes of ritual, and codes of morals represents the first attempt at a solution of the problem: the modern rise of arbitration as a method of settling disputes between whole units and large groups within units is another important step in the same direction. Nevertheless, it is here that the most drastic change of method will have to be brought into being if man’s development is to continue progressive.