The extraordinary confusion of thought involved in Mr. Spencer’s position is focalised in an argument constantly employed by socialists—that “_inventions once made, become common property_.” Except the earliest and simplest of them, they no more become common property than the countless facts and figures buried in Parliamentary Blue-Books become the property of every new member of Parliament, or than encyclopædic knowledge becomes the property of every one who happens to inherit an edition of the _Encyclopædia Britannica_; or than the power of deciphering the hieroglyphics which are preserved in the British Museum becomes the property of every cabman who drives his vehicle along Great Russell Street. It is perfectly true that the discovery of each new portion of knowledge enables men to acquire it who never might have discovered it for themselves; but as the acquisition of the details of knowledge becomes facilitated, the number of details to be acquired increases at the same time; and the increased ease of acquiring each is accompanied by an increased difficulty in acquiring all, or even in assimilating those which are practically connected with one another. A mechanic, for instance, could with ten minutes’ attention comprehend the principle involved in a cantilever bridge, but to design and construct a bridge such as that which now spans the {82} Forth, with its spans of six hundred yards and its altitudes of aerial steel, implies an assimilation of our multitudinous existing knowledge, such as is hardly to be found in a score of engineers in Europe. Or to turn once more to Mr. Spencer’s example of Shakespeare, whilst all Shakespeare’s contemporaries had the same antecedents that he had, the same line of thinkers behind them, and the same developed vocabulary, Shakespeare’s mind was capable of absorbing much of the national inheritance, whilst the great mass of his contemporaries could comparatively absorb very little. We are thus brought back to the point from which we set out—namely, the differences in capacity by which men are distinguished from one another; and we see that all the reasonings of our modern sociologists have, for practical purposes, left these differences undiminished. The difference between the great man and the ordinary man is not made less by the fact that they both of them owe much to a common past, any more than the difference between a hogshead of water and a wine-glass is made less by the fact that both have been filled from the same stream.