76 GENIUS AND MENTAL DISEASE. 
no reason to suspect it hath at all touched his under- 
standing.’’ Huygens, a contemporary scientist, says, in 
a letter to Leibnitz in 1694, that Newton was ill for 
about eighteen months with phrenitis or brain-fever, 
from which he recovered by the use of medicines. With 
these data before us, it is a misconception of physiologi- 
cal and pathological facts to assert that Newton was in- 
sane: and that there was a kinship between his mighty 
genius and madness, is contradicted by the intellectual 
work which has given immortality to his name. 
The star seen by Napoleon, which was to him an omen 
of success; the vision which came to Cromwell, and 
spoke the words prophetic of his greatness ; the appari- 
tion which uttered the ominous words to Brutus—‘‘I 
am thy evil genius, thou wilt meet me at Phillipi!” 
the dreams and visions of Benvenuto Cellini; the ‘‘ trees 
like men walking,’ as seen by Sir Joshua Reynolds, 
and the appearance of the devil to Luther—are all ex- 
amples of hallucinations which are entirely consistent 
with reason, and are not justly indicative of insanity or 
mental disease. They represent a habit of mind which 
naturally, under conditions of concentrated attention, 
intensified in an age tolerant of all forms of supersti- 
tions, ‘‘seeks for and creates, if need be, with or with- ~ 
out consciousness, an outward object as the cause of its 
feelings.”’ Luther, for example, saw with his ‘‘mind’s 
eye’ the image of the devil, which, in that age of re- 
ligious excitement and credulity, was ever expectant in 
all minds, and generally present everywhere. ‘‘ Hallu- 
cinations were,’’ says De Boismont, ‘“‘in the whole 
social community, not in individuals’’; and hence it 
was that under the dominion of a general belief, how- 
ever vague or irrational it may have been, the individual 
mind ‘‘ demanded of imagination the realization of the 
phantasms of its dreams; and imagination, despite of 
resistance of reason, endowed them with form and sub- 
