To explain this flickering mood, one is abandoned to one’s own insight into the nature of the man and into the conditions of his problem. In the first connection, we make it out that Hume’s genial bearing before men cloaked, in a seemly well-bred fashion, a deep seriousness of character, just as the light tone of certain of Plato’s dialogues is chosen as a fit medium for the setting forth of lofty ideas in polite company. At sixteen, before he had acquired this _pudeur_ of high sounding discourse, we find him writing to his friend Michael Ramsay with the shameless solemnity of a Roman sage: “The perfectly wise man that outbraves fortune is much greater than the husbandman who slips by her, and indeed that pastoral and saturnian happiness I have in a great measure come at just now--” and more of the like! We may safely take it that the sage of sixteen had not died in the man of sixty, for all that the latter preferred to talk with his worldly friends of “_soupe à la reine_ and beef and cabbage (a charming dish).” Well, then, in common with most natures possessed of a like “high seriousness,” Hume would have preferred to see the world in a religious light, would instinctively have looked in it too for high purpose. And this high purpose, he seemed to see it out of the corner of his eye as one does the first star in the twilight. But when he sought it with full, clear vision--it was gone. The reason for this phenomenon may, perhaps, lie in the nature of the problem as Hume habitually thought of it. It was, there could be no doubt of it, the order and uniformity of nature that was to reveal to us an intelligent cause. But in daily life, as in the highest philosophy, we recognize two kinds of order and uniformity in our experience. It is an established rule that a stone will fall to the earth, that all stones will fall in the same way, that a single law describes a behavior common to this stone’s falling and to the planets’ swinging in their orbits, a law we imagine to hold for every particle of matter in the universe in its reaction toward every other, and which we call the law of gravitation. The law of gravitation is about as high an expression of a uniformity holding throughout nature as we have as yet come upon. Such laws as those of physics and chemistry are among the best attested results of experience, and we may stare at them quite boldly without fear of putting them out of countenance; but then, too, we may examine them as intently as we will without finding in them the revelation of an intelligence that framed them. For merely as such laws they make no reference to a purpose to which the mechanism they govern is adapted.