There are certain great ideas which, if we have any intelligence and thoughtfulness at all, we cannot help coming across the track of, just as when we walk far into the deep country, in the time of the blossoming of flowers, we step for a moment into a waft of fragrance, cast upon the air from orchard or thicket or scented field of bloom.

These ideas are very various in quality; some of them deliciously haunting and transporting, some grave and solemn, some painfully sad and strong. Some of them seem to hint at unseen beauty and joy, some have to do with problems of conduct and duty, some with the relation in which we wish to stand or are forced to stand with other human beings; some are questionings born of grief and pain, what the meaning of sorrow is, whether pain has a further intention, whether the spirit survives the life which is all that we can remember of existence; but the strange thing about all these ideas is that we find them suddenly in the mind and soul; we do not seem to invent them, though we cannot trace them; and even if we find them in books that we read or words that we hear, they do not seem wholly new to us; we recognise them as things that we have dimly felt and perceived, and the reason why they often have so mysterious an effect upon us is that they seem to take us outside of ourselves, further back than we can recollect, beyond the faint horizon, into something as wide and great as the illimitable sea or the depths of sunset sky.

Some of these ideas have to do with the constitution of society, the combined and artificial peace in which human beings live, and then they are political ideas; or they deal with such things as numbers, curves, classes of animals and plants, the soil of the earth, the changes of the seasons, the laws of weight and mass, and then they are scientific ideas; some have to do with right and wrong conduct, actions and qualities, and then they are religious or ethical ideas. But there is a class of thoughts which belong precisely to none of these things, but which are concerned with the perception of beauty, in forms and colours, musical sounds, human faces and limbs, words majestic or sweet; and this sense of beauty may go further, and may be discerned in qualities, regarded not from the point of view of their rightness and justice, but according as they are fine and noble, evoking our admiration and our desire; and these are poetical ideas.

It is not of course possible exactly to classify ideas, because there is a great overlapping of them and a wide interchange. The thought of the slow progress of man from something rude and beastlike, the statement of the astronomer about the swarms of worlds swimming in space, may awaken the sense of poetry which is in its essence the sense of wonder. I shall not attempt in these few pages to limit and define the sense of poetry. I shall merely attempt to describe the kind of effect it has or may have in life, what our relation is or may be to it, what claim it may be said to have upon us, whether we can practise it, and whether we ought to do so.