basis of both. Here we meet that hoary sinner, the 'uncaused cause' about which, to our modern amazement, the science and philosophy of that day are agreed entirely.
Passing to England, we find Locke confronted by a different problem, but the setting remains identical. Assuming, like Newton and Descartes, two separate factors—others assumed many, but the number makes no essential difference—and asking. How do I, who am inside, get my knowledge of things, which are outside? Under the circumstances, the obvious reply is, through the senses. The senses write upon the mind. Unfortunately, this information about the external world lacks directness, for the senses are modifications of the bodily organism and therefore tell nothing about the real objects. How, then, placed in such a dilemma, do we know objects? Locke alleges that Substance, a thing which we do not perceive, but which we are compelled to infer, originates the conviction of permanence associated with reality in objects. Here, once more, a third thing, belonging to neither of the factors under review, plays the part of Newton's agent and of the Cartesian deity. Without condescending upon further details, it is easy to see why science and philosophy could not well fall out during the period when such conceptions held sway. But this agreement, happy in its unconsciousness of problems at all events, was not to endure forever. The world of human experience revealed new aspects, and fresh questions, sources of dire controversy, loomed upon the horizon. The dynamic, molecular and organic modes of thought, with their attendant conception of the universe, were destined to elbow out the static and mechanical.
Even amid many seeming transformations, the 'Newtonian philosophy preserved itself unchanged in essentials. The Deistic movement, Butler's 'Analogy,' Pope's 'Essay on Man' and Paley's 'Natural Theology,' and the highly wrought productions of the great French physicists, culminating in Laplace's 'Mécanique Céleste,' even the Scottish 'common-sense' protest against current scepticism, all emerged on the basis of its first principles. But, after the middle of the eighteenth century, three men shook it to its foundations and made possible the new structure we now call 'modern' thought. These men were Hume, Kant and Herder; the half-conscious protest of Spinoza had passed over the heads of his contemporaries unheeded. Was he not a Jew, a pantheist and, therefore, a flat blasphemer? The joint performance of this eighteenth century trinity, 'equal in power and glory,' raises problems of the most complicated kind, so complicated, indeed, that they have been the bugbear even of expert students during the last two generations. I can attempt here to put the salient points only, as clearly as possible.
Many pious efforts to understand Hume have been frustrated by
