"
III.
THE CASE OF MR. FOGGATT.
Almost the only dogmatism that Martin Hewitt permitted himself in regard
to his professional methods was one on the matter of accumulative
probabilities. Often when I have remarked upon the apparently trivial
nature of the clews by which he allowed himself to be guided--sometimes,
to all seeming, in the very face of all likelihood--he has replied that
two trivialities, pointing in the same direction, became at once, by their
mere agreement, no trivialities at all, but enormously important
considerations. "If I were in search of a man," he would say, "of whom I
knew nothing but that he squinted, bore a birthmark on his right hand, and
limped, and I observed a man who answered to the first peculiarity, so far
the clue would be trivial, because thousands of men squint. Now, if that
man presently moved and exhibited a birthmark on his right hand, the
value of that squint and that mark would increase at once a hundred or
a thousand fold. Apart they are little; together much. The weight of
evidence is not doubled merely; it would be only doubled if half the men
who squinted had right-hand birthmarks; whereas the proportion, if it
could be ascertained, would be, perhaps, more like one in ten thousand.
Pages:
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100