A convention may be defined as something which a number of men have agreed to accept in lieu of the truth and to pass off for the truth upon others: I was about to add, preferably when they can catch them young: but some recent travel in railway trains and listening to the kind of stuff men of mature years deliver straight out of newspapers for the products of their own digested thought have persuaded me that the ordinary man is as susceptible at fifty, sixty, or even seventy as at any earlier period of growth, and that the process of incubation is scarcely less rapid. I am not, to be sure, concerned to deny that there may be conventions useful enough to society, serving it to maintain government, order, public and private decency, or the commerce on which it must needs rest to be a civilised society at all-- commerce of food, commerce of clothing, and so on, up to commerce in knowledge and ideas. Government itself--any form of it--is a convention; marriage is a convention; money of course is a convention, and the alphabet itself I suppose to contain as many conventions as all the old Courts of Love and Laws of Chivalry put together, and our English alphabet one tremendous fallacy, that twenty-six letters, separately or in combination are capable of symbolising all the sounds produced by an Englishman's organs of speech, let alone the sounds he hears from foreigners, dogs, guns, steam-engines, motor-horns and other friends and enemies to whom we deny the franchise. Also of course it ignores the whole system of musical notes--another convention--which yet with many of the older bards could hardly be separated from the words they used, though now only the words survive and as literature. IV But every convention has a fallacy somewhere at the root; whether it be useful and operative, as many a legal fiction is operative, for good; or senile, past service yet tyrannous by custom, and so pernicious; or merely foolish, as certain artistic conventions are traceable, when a Ruskin comes to judgment, back to nothing better than folly: and it becomes men of honest mind, in dealing with anything recognisable as a convention, to examine its accepted fallacy, whether it be well understood or ill understood; beneficent or pernicious or merely foolish or both foolish and pernicious: and this is often most handily done by tracing its history.