Humour has its place, a respectable one too, in essays and other forms of literature which deal directly with reality and are products not so much of imagination as of thought. In these, the contrast between the serious and the playful appears in transitions from a perfectly grave to a humorous kind of reflection. Marked differences of tone are observable here also. The humorous remark may be but a momentary diversion of the attention, a playful side-glance, in a serious argument. In some writings, _e.g._, those of Sir Thos. Browne and of Lamb, the humorous element hardly amounts to a digression, or even to a momentary interruption, but is fused into and half lost to sight in the serious argument.[325] Among more recent writers, too, including some yet living, we have admirable examples of historical narrative {391} and criticism lit up here and there with soft glow-worm points of humour. In other cases, the humorous feature may be so large as to modify the colour of the whole, as in Miss Kingsley’s _Travels in West Africa_. An Essay, again, may be as a whole a _jeu d’esprit_ and the fun seem to preponderate, while the manner is throughout that of grave argument; or, in more subtle work, as some of Charles Lamb’s, it may be best described as fun sandwiched in between a look of seriousness on the surface, and a real seriousness of meaning below. The fusion of tones leaves much to be desired in the case of many writers who are popularly regarded as skilled humorists. A mere interruption of serious thought by a sort of playful “aside” does not prove the existence of the gift of humour, which is essentially the power of playing on moods not only dissimilar but usually antagonistic in a way that avoids all shock and sense of discontinuity. {392} CHAPTER XII. ULTIMATE VALUE AND LIMITATIONS OF LAUGHTER. Our study has taken us through various regions of research. In looking for the germ of laughter we found ourselves in the wide and misty plains of biological speculation. In tracing its development we took a dip into the pleasant vales of child-psychology and anthropology, and then tried to climb the winding paths of social evolution. Having reached in this way the heights of modern civilisation, we made a special investigation into the social organisation of laughter, as represented in the art of comedy, and into the gradual appearance of a new type of laughter, essentially individual and independent of the social standard, to which is given the name of humour. Throughout this voyage of discovery we have kept in view the question of the function of the laughing spirit in the life of the individual and of the community. It remains to determine this function more precisely.