We are familiar with the fact that faint memories are very apt to become confused.  Thus some picture of mountain and lake in a country which we have never visited, often recalls a vague sense of identity with much we have seen elsewhere.  Our recollections cannot be disentangled, though general resemblances are recognised.  It is also a fact that the memories of persons who have great powers of visualising, that is, of seeing well-defined images in the mind’s eye, are no less capable of being blended together.  Artists are, as a class, possessed of the visualising power in a high degree, and they are at the same time pre-eminently distinguished by their gifts of generalisation.  They are of all men the most capable of producing forms that are not copies of any individual, but represent the characteristic features of classes.

There is then, no doubt, from whatever side the subject of memory is approached, whether from the material or from the mental, and, in the latter case, whether we examine the experiences of those in whom the visualising faculty is faint or in whom it is strong, that the brain has the capacity of blending memories together.  Neither can there be any doubt that general impressions are faint and perhaps faulty editions of blended memories.  They are subject to errors of their own, and they inherit all those to which the memories are themselves liable.

Specimens of blended portraits will now be exhibited; these might, with more propriety, be named, according to the happy phrase of Professor Huxley, “generic” portraits.  The word generic presupposes a genus, that is to say, a collection of individuals who have much in common, and among whom medium characteristics are very much more frequent than extreme ones.  The same idea is sometimes expressed by the word “typical,” which was much used by Quetelet, who was the first to give it a rigorous interpretation, and whose idea of a type lies at the basis of his statistical views.  No statistician dreams of combining objects into the same generic group that do not cluster towards a common centre; no more should we attempt to compose generic portraits out of heterogeneous elements, for if we do so the result is monstrous and meaningless.

It might be expected that when many different portraits are fused into a single one, the result would be a mere smudge.  Such, however, is by no means the case, under the conditions just laid down, of a great prevalence of the mediocre characteristics over the extreme ones.  There are then so many traits in common, to combine and to reinforce one another, that they prevail to the exclusion of the rest.  All that is common remains, all that is individual tends to disappear.