It is a remarkable fact, which may easily be misinterpreted, that while all the benefits and pleasures of life seem to be associated with external things, and all certain knowledge seems to describe material laws, yet a deified nature has generally inspired a religion of melancholy. Why should the only intelligible philosophy seem to defeat reason and the chief means of benefiting mankind seem to blast our best hopes? Whence this profound aversion to so beautiful and fruitful a universe? Whence this persistent search for invisible regions and powers and for metaphysical explanations that can explain nothing, while nature’s voice without and within man cries aloud to him to look, act, and enjoy? And when someone, in protest against such senseless oracular prejudices, has actually embraced the life and faith of nature and taught others to look to the natural world for all motives and sanctions, expecting thus to refresh and marvellously to invigorate human life, why have those innocent hopes failed so miserably? Why is that sensuous optimism we may call Greek, or that industrial optimism we may call American, such a thin disguise for despair? Why does each melt away and become a mockery at the first approach of reflection? Why has man’s conscience in the end invariably rebelled against naturalism and reverted in some form or other to a cultus of the unseen? [Sidenote: The soul akin to the eternal and ideal.] We may answer in the words of Saint Paul: because things seen are temporal and things not seen are eternal. And we may add, remembering our analysis of the objects inhabiting the mind, that the eternal is the truly human, that which is akin to the first indispensable products of intelligence, which arise by the fusion of successive images in discourse, and transcend the particular in time, peopling the mind with permanent and recognisable objects, and strengthening it with a synthetic, dramatic apprehension of itself and its own experience. Concretion in existence, on the contrary, yields essentially detached and empirical unities, foreign to mind in spite of their order, and unintelligible in spite of their clearness. Reason fails to assimilate in them precisely that which makes them real, namely, their presence here and now, in this order and number. The form and quality of them we can retain, domesticate, and weave into the texture of reflection, but their existence and individuality remain a datum of sense needing to be verified anew at every moment and actually receiving continual verification or disproof while we live in this world.