and Addison:—­“It is much easier to decide what is not humorous than what is, and very difficult to define it otherwise than Cowley has done, by negatives”—­the only meaning of which is that the subject is surrounded with rather more than the usual difficulties attending moral and psychological researches.  Similar obstacles would be encountered in answering the question, “What is poetry?” or “What is love?” We can only say that even here there must be some surroundings by which we can increase our knowledge.

Humour is the offspring of man—­it comes forth like Minerva fully armed from the brain.  Our sense of the ludicrous is produced by our peculiar mental constitution, and not by external objects, in which there is nothing either absurd or serious.  As when the action of our mind is imperceptible—­for instance, in hearing and seeing with our “bodily” senses—­we think what we notice is something in the external world, although it is only so far dependent upon it that it could not exist without some kind of outer influence, so the result of our not recognising the amusing action of the mind in the ludicrous is that we regard it as a quality resident in the persons and things we contemplate.[1] But it does not belong to these things, and is totally different from them in kind.  Thus, the rose is formed of certain combinations of earth, air, and water; yet none of these dull elements possess the fragrance or beauty of the flower.  These properties come from some attractive and constructive power.  Not only are there no types or patterns in things of our emotions, but there are none even of our sensations; heat and cold, red or blue, are such only for our constitution.  This truth is beautifully set forth by Addison in a passage in which, as Dugald Stewart justly remarks, “We are at a loss whether most to admire the author’s depth and refinement of thought, or the singular felicity of fancy displayed in its illustration.”  “Things,” he observes, “would make but a poor appearance to the eye, if we saw them only in their proper figures and motions.  And what reason can we assign for their exciting in us many of those ideas which are different from anything that exists in the objects themselves (for such are light and colours) were it not to add supernumerary ornaments to the universe, and make it more agreeable to the imagination?  We are everywhere entertained with pleasing shows and apparitions.  We discover imaginary glories in the heavens and on the earth, and see some of this visionary beauty poured out over the whole creation.  But what a rough, unsightly sketch of Nature should we be entertained with, did all her colouring disappear, and the several distinctions of light and shade vanish!  In short, our souls are delightfully lost and bewildered in a pleasing delusion, and we walk about like the enchanted hero of a romance, who sees beautiful castles, woods, and meadows, and at the same time hears the warbling of birds and the purling of streams; but upon the finishing of some secret spell, the fantastic scene breaks up, and the disconsolate knight finds himself on a barren heath, or in a solitary desert.”