visible universe has led us to the recognition of a kind of unseen world underlying the world of things that are seen, yet concerning the economy of this unseen world we have not been led to entertain any hypothesis that has not its possible justification in our experiences of visible phenomena. We are now called upon, following in the wake of our esteemed authors, to venture on a different sort of exploration, in which we must cut loose altogether from our moorings in the world of which we have definite experience. We are invited to entertain suggestions concerning the peculiar economy of the invisible portion of the universe which we have no means of subjecting to any sort of test of probability, either experimental or deductive. These suggestions are, therefore, not to be regarded as properly scientific; but, with this word of caution, we may proceed to show what they are. Compared with the life and death of cosmical systems which we have heretofore contemplated, the life and death of individuals of the human race may perhaps seem a small matter; yet because we are ourselves the men who live and die, the small event is of vastly greater interest to us than the grand series of events of which it is part and parcel. It is natural that we should be more interested in the ultimate fate of humanity than in the fate of a world which is of no account to us save as our present dwelling-place. Whether the human soul is to come to an end or not is to us a more important question than whether the visible universe, with its matter and energy, is to be absorbed in an invisible ether. It is indeed only because we are interested in the former question that we are so curious about the latter. If we could dissociate ourselves from the material universe, our habitat, we should probably speculate much less about its past and future. We care very little what becomes of the black ball of the earth, after all life has vanished from its surface; or, if we care at all about it, it is only because our thoughts about the career of the earth are necessarily mixed up with our thoughts about life. Hence in considering the probable ultimate destiny of the physical universe, our innermost purpose must be to know what is to become of all this rich and wonderful life of which the physical universe is the theatre. Has it all been developed, apparently at almost infinite waste of effort, only to be abolished again before it has attained to completeness, or does it contain or shelter some indestructible element which having drawn sustenance for a while from the senseless turmoil of physical phenomena shall still survive their final decay? This question is closely connected with the time-honoured question of the meaning, purpose, or tendency of the world. In the career of the world is life an end, or a means toward an end, or only an incidental phenomenon in which we can discover no meaning? Contemporary theologians seem generally to believe that one necessary result of