first line, because mathematics are to me only a concept: I never
used a logarithm in my life, and could not undertake to extract
the square root of four without misgiving. I am therefore unable
to deny that the statistical ascertainment of the correlations
between one thing and another must be a very complicated and
difficult technical business, not to be tackled successfully
except by high mathematicians; and I cannot resist Professor Karl
Pearson's immense contempt for, and indignant sense of grave
social danger in, the unskilled guesses of the ordinary
sociologist.

Now the man in the street knows nothing of Biometrika: all he
knows is that "you can prove anything by figures," though he
forgets this the moment figures are used to prove anything he
wants to believe. If he did take in Biometrika he would probably
become abjectly credulous as to all the conclusions drawn in it
from the correlations so learnedly worked out; though the
mathematician whose correlations would fill a Newton with
admiration may, in collecting and accepting data and drawing
conclusions from them, fall into quite crude errors by just such
popular oversights as I have been describing.


PATIENT-MADE THERAPEUTICS

To all these blunders and ignorances doctors are no less subject
than the rest of us. They are not trained in the use of evidence,
nor in biometrics, nor in the psychology of human credulity, nor
in the incidence of economic pressure. Further, they must
believe, on the whole, what their patients believe, just as they