230 Life and Letters of Francis Galton
another, and then held between the eye and the light. I have attempted this with some success. My own idea was to throw faint images of the several portraits, in succession, upon the same sensitised photographic plate. I may add that it is perfectly easy to superimpose optically two portraits by means of a stereoscope and that a person who is used to handling instruments will find a common double eye-glass fitted with stereoscopic lenses to be almost as effectual and far handier than the boxes sold in shops'." (pp. 9-10.)
Thus was launched the first idea of composite photographs. But Galton very rarely made a suggestion without already having applied it himself', and in this case he had chosen as his subject "the criminals of England who have been condemned to long terms of penal servitude for various heinous crimes."
He had formed his own views on "the ideal criminal." He has three peculiarities of character: (i) his conscience is almost deficient, (ii) his instincts are vicious, and (iii) his power of self-control is very weak. His instincts determine the description of his crime, and the absence of selfcontrol may be due to ungovernable temper, to sensual passion, or to mere imbecility.
Galton as a biologist is very cautious in his discussion of "vicious instincts." He says
"The subject of vicious instincts is a very large one: we must guard ourselves against looking upon them as perversions, inasmuch as they may be strictly in accordance with the healthy nature of the man, and being transmissible by inheritance, may become the normal characteristics of a healthy race, just as the sheep-dog, the retriever, the pointer, the bull-dog have their several instincts. There can be no greater popular error than the supposition that natural instinct is a perfectly trustworthy guide, for there are striking contradictions to such an opinion in individuals of every description of animal. All that we are entitled to say is, that the prevalent instincts of each race are trustworthy, not those of every individual. A man who is counted as an atrocious criminal by society, and is punished as such by law may nevertheless have acted in strict accordance with his instincts. The ideal criminal is deficient in qualities that oppose his vicious instincts; he has neither the natural regard for others which lies at the base of conscience, nor has he sufficient self-control to enable him to consider his own selfish interests in the long run. He cannot be preserved from criminal mis-adventure, either by altruistic or by intelligently egoistic sentiments." (pp. 11-12.)
Having defined the mental characters which he considers peculiar to the criminal Galton next proceeded to investigate how far these peculiarities are correlated with the physical characters, in particular with the physiognomy. He divided his criminals into three main groups taking in all cases the photographs' only of men sentenced to long terms of penal servitude-; the groups were (a) Murder, Manslaughter and Burglary, (b) Felony and Forgery, (c) Sexual offences. Galton believed that by continually sorting the photographs in tentative ways certain natural classes began to appear, some very well marked, and that the proportion of these in the three crime
' Galton's double eyeglass with stereoscopic lenses is in the Galtoniana.
Q I think an exception must be made to this rule in the case of the four aspects on our photographic plates referred to above. But I may have overlooked some possible mirror arrangement, and if not we have to remember that Galton's address was prepared in great haste, for he had been suddenly called upon to occupy the chair owing to the ethnologist who would otherwise have presided being debarred by illness.
a Identification photographs of the Home Office provided by the Surveyor-General of Prisons, Sir Edmund Du Cane.