Loving man as Wordsworth did, he was most anxious to give him this teaching. How was he to do it? By poetry. Nature put into the crucible of a loving heart becomes poetry. We cannot explain poetry scientifically; because poetry is something beyond science. The poet may be man of science, and the man of science may be a poet; but poetry includes science, and the man who will advance science most, is the man who, other qualifications being equal, has most of the poetic faculty in him. Wordsworth defines poetry to be “the impassioned expression which is on the face of science.” Science has to do with the construction of things. The casting of the granite ribs of the mighty earth, and all the thousand operations that result in the manifestations on its surface, this is the domain of science. But when there come the grass-bearing meadows, the heaven-reared hills, the great streams that go ever downward, the bubbling fountains that ever arise, the wind that wanders amongst the leaves, and the odours that are wafted upon its wings; when we have colour, and shape, and sound, then we have the material with which poetry has to do. Science has to do with the underwork. For what does this great central world exist, with its hidden winds and waters, its upheavings and its downsinkings, its strong frame of rock, and its heart of fire? What do they all exist for? Not for themselves surely, but for the sake of this out-spreading world of beauty, that floats up, as it were, to the surface of the shapeless region of force. Science has to do with the one, and poetry with the other: poetry is “the impassioned expression that is on the face of science.” To illustrate it still further. You are walking in the woods, and you find the first primrose of the year. You feel almost as if you had found a child. You know in yourself that you have found a new beauty and a new joy, though you have seen it a thousand times before. It is a primrose. A little flower that looks at me, thinks itself into my heart, and gives me a pleasure distinct in itself, and which I feel as if I could not do without. The impassioned expression on the face of this little outspread flower is its childhood; it means trust, consciousness of protection, faith, and hope. Science, in the person of the botanist, comes after you, and pulls it to pieces to see its construction, and delights the intellect; but the science itself is dead, and kills what it touches. The flower exists not for it, but for the expression on its face, which is its poetry,--that expression which you feel to mean a living thing; that expression which makes you feel that this flower is, as it were, just growing out of the heart of God. The intellect itself is but the scaffolding for the uprearing of the spiritual nature.