§ 1. The problem of the One and the Many is as old as Philosophy itself, and inevitably arises from the earliest and simplest attempts to think in a consistent way about the nature of the world in which we play our part. On the one hand, our experience, in the piecemeal shape in which it first appears as we begin to reflect on it, seems to exhibit an indefinite plurality of more or less independent things, each pursuing its own course and behaving in its own way, and connected at best with only a few of the other members of our environment. There is, for instance, no obvious connection between one man’s career and those of most of his contemporaries, to say nothing of the innumerable host of his predecessors and successors in the race of life. And, similarly, the behaviour of one inanimate thing seems at first sight to be unaffected by that of most of the other things around it. The world seems to us at times to be made up of an indefinite multiplicity of beings who merely happen to be actors on the same stage, but have, in the majority of cases, no influence upon each other’s parts. Yet, on the other hand, there are equally strong _primâ facie_ reasons for regarding the world as a single unity. Every addition to our theoretical insight into the structure of things adds to our recognition of the intimate connection between things and processes which previously seemed merely disconnected. Physical science, as it grows, learns more and more to look upon nature as a realm of interconnected events where no one fact is ultimately entirely independent of any other fact; political experience and social science alike reveal the intimate interdependence of human lives and purposes. And, over and above the ascertained empirical facts which point to the ultimate unity of the world, there is another potent influence which we might call the “instinctive” basis for the belief in unity. However discontinuous my environment may appear, it is never a mere disconnected multiplicity. The very circumstance that it is throughout _my_ environment, and thus relative to the ends by which my attention is determined, gives it to a certain degree the character of a coherent system. At the lowest level of philosophic reflection, we cannot permanently fail to apprehend our world as in principle one, precisely because it is _our_ world, and we ourselves are all in some degree beings of steady systematic purpose, not mere bundles of disconnected and conflicting impulses. While yet again, it is the very limitation of our own interests and our lack of clear insight into their full import which leads us at other times to find apparent disconnected multiplicity and lack of cohesion in our world.