As a body of practical rules, the negative precepts of asceticism bring with them a certain chill.  The page is dull; it is so easy to lighten it with some flash of witty irrelevance:  the argument is long and tedious, why not relieve it by wandering into some of those green enclosures that open alluring doors upon the wayside?  To roam at will, spring-heeled, high-hearted, and catching at all good fortunes, is the ambition of the youth, ere yet he has subdued himself to a destination.  The principle of self-denial seems at first sight a treason done to genius, which was always privileged to be wilful.  In this view literature is a fortuitous series of happy thoughts and heaven-sent findings.  But the end of that plan is beggary.  Sprightly talk about the first object that meets the eye and the indulgence of vagabond habits soon degenerate to a professional garrulity, a forced face of dismal cheer, and a settled dislike of strenuous exercise.  The economies and abstinences of discipline promise a kinder fate than this.  They test and strengthen purpose, without which no great work comes into being.  They save the expenditure of energy on those pastimes and diversions which lead no nearer to the goal.  To reject the images and arguments that proffer a casual assistance yet are not to be brought under the perfect control of the main theme is difficult; how should it be otherwise, for if they were not already dear to the writer they would not have volunteered their aid.

It is the more difficult, in that to refuse the unfit is no warrant of better help to come.  But to accept them is to fall back for good upon a makeshift, and to hazard the enterprise in a hubbub of disorderly claims.  No train of thought is strengthened by the addition of those arguments that, like camp-followers, swell the number and the noise, without bearing a part in the organisation.  The danger that comes in with the employment of figures of speech, similes, and comparisons is greater still.  The clearest of them may be attended by some element of grotesque or paltry association, so that while they illumine the subject they cannot truly be said to illustrate it.  The noblest, including those time-honoured metaphors that draw their patent of nobility from war, love, religion, or the chase, in proportion as they are strong and of a vivid presence, are also domineering—­apt to assume command of the theme long after their proper work is done.  So great is the headstrong power of the finest metaphors, that an author may be incommoded by one that does his business for him handsomely, as a king may suffer the oppression of a powerful ally.  When a lyric begins with the splendid lines,

Love still has something of the sea
From whence his mother rose,

the further development of that song is already fixed and its knell rung—­to the last line there is no escaping from the dazzling influences that presided over the first.  Yet to carry out such a figure in detail, as Sir Charles Sedley set himself to do, tarnishes the sudden glory of the opening.  The lady whom Burns called Clarinda put herself in a like quandary by beginning a song with this stanza —