If we admit that we cannot explain what it is in its ultimate nature, we are yet all of us conscious enough of what we mean ourselves by life. The word has a real significance to us, although we cannot define it or explain it in any way.
Can we then find any answer from physical science as to whether or no our life continues when the bodily change which we call death happens? Since life is always connected, as far as we are able to observe it, with certain physical conditions of the body, can it continue when those conditions are no longer present?
There have been many thinkers impressed by the sense of a universe governed by necessary and unchanging laws, who have felt that they could only answer that since life is in our experience always accompanied by certain material conditions, it must cease to exist when those conditions have been removed.
There is one great assumption, however, which consciously or unconsciously underlies this position, that the only universe which exists is one that is intelligible to our thought, and that something [p.121] which we cannot possibly understand, necessarily cannot possibly exist.
But there is yet another thought which seems to have escaped such a thinker: the possibility of the co-existence of more than one world and of life passing from one world to another. Mathematicians have already shown the possibility of this by discussing the existence of a fourth dimension, and even working out problems involving the assumption of the existence of this fourth dimension. The suggestion has been made especially easy to grasp in the remarkable anonymous romance "Flatland," published some thirty years ago, which pictures the world of two dimensions, wherein one person gets the notion of the existence of a third dimension, and the extraordinary results that follow his heresy, or madness, as it seems to his less enlightened fellows.
If the theory of the existence of another, or other dimensions be a tenable one, we can conceive of the existence of a number of worlds around us, co-existing with our own and including it, of which we are either wholly unconscious or only very dimly conscious, and that not by the faculties by means of which we have knowledge of our own world.