Sometimes we sailed as gently and steadily as the clouds overhead, watching the receding shores and the motions of our sail; the play of its pulse so like our own lives, so thin and yet so full of life, so noiseless when it labored hardest, so noisy and impatient when least effective; now bending to some generous impulse of the breeze, and then fluttering and flapping with a kind of human suspense. It was the scale on which the varying temperature of distant atmospheres was graduated, and it was some attraction for us that the breeze it played with had been out of doors so long. Thus we sailed, not being able to fly, but as next best, making a long furrow in the fields of the Merrimack toward our home, with our wings spread, but never lifting our heel from the watery trench; gracefully ploughing homeward with our brisk and willing team, wind and stream, pulling together, the former yet a wild steer, yoked to his more sedate fellow. It was very near flying, as when the duck rushes through the water with an impulse of her wings, throwing the spray about her, before she can rise. How we had stuck fast if drawn up but a few feet on the shore!

When we reached the great bend just above Middlesex, where the river runs east thirty-five miles to the sea, we at length lost the aid of this propitious wind, though we contrived to make one long and judicious tack carry us nearly to the locks of the canal. We were here locked through at noon by our old friend, the lover of the higher mathematics, who seemed glad to see us safe back again through so many locks; but we did not stop to consider any of his problems, though we could cheerfully have spent a whole autumn in this way another time, and never have asked what his religion was. It is so rare to meet with a man out-doors who cherishes a worthy thought in his mind, which is independent of the labor of his hands. Behind every man's busy-ness there should be a level of undisturbed serenity and industry, as within the reef encircling a coral isle there is always an expanse of still water, where the depositions are going on which will finally raise it above the surface.

The eye which can appreciate the naked and absolute beauty of a scientific truth is far more rare than that which is attracted by a moral one. Few detect the morality in the former, or the science in the latter. Aristotle defined art to be , _The principle of the work without the wood_; but most men prefer to have some of the wood along with the principle; they demand that the truth be clothed in flesh and blood and the warm colors of life. They prefer the partial statement because it fits and measures them and their commodities best. But science still exists everywhere as the sealer of weights and measures at least.

We have heard much about the poetry of mathematics, but very little of it has yet been sung. The ancients had a juster notion of their poetic value than we. The most distinct and beautiful statement of any truth must take at last the mathematical form. We might so simplify the rules of moral philosophy, as well as of arithmetic, that one formula would express them both. All the moral laws are readily translated into natural philosophy, for often we have only to restore the primitive meaning of the words by which they are expressed, or to attend to their literal instead of their metaphorical sense. They are already _supernatural_ philosophy. The whole body of what is now called moral or ethical truth existed in the golden age as abstract science. Or, if we prefer, we may say that the laws of Nature are the purest morality. The Tree of Knowledge is a Tree of Knowledge of good and evil.