[21] A. Baer: Der Verbrecher Leipzig 1893.
[22] Koch. Die Frage nach dem geborenen Verbrecher. Ravensberg 1894.
[23] Maschka. Elandbuch der Gerichtlichen Medizin (vol. IV). T
bingen 1883.
[24] Thomson. Psychologie der Verbrecher.
[25] Ferri: Gerichtl. Psychologie. Mailand 1893.
[26] Bonfigli: Die Natugeschichte des Verbrechers. Mailand 1892.
[27] Corre: Les Criminels. Paris 1889.
Literally, criminal psychology should be _that form of psychology
used in dealing with crime_; not merely, the psychopathology of
criminals, the natural history of the criminal mind. But taken even
literally, this is not all the psychology required by the criminalist.
No doubt crime is an objective thing. Cain would actually have
slaughtered Abel even if at the time Adam and Eve were already
dead. But for us each crime exists only as we perceive it,--as we
learn to know it through all those media established for us in criminal
procedure. But these media are based upon sense-perception, upon
the perception of the judge and his assistants, i. e.: upon witnesses,
accused, and experts. Such perceptions must be psychologically
validated. The knowledge of the principles of this validation
demands again a special department of general psychology--even
