VI.
PREFACE.
laboratory, read an elementary book on biology—is doubt
less good advice; and yet a man might thus get the
merest smattering of knowledge, or might easily become
so absorbed in the comprehension of the details as to lose
the grasp of the general idea. Who would think of de
manding that the judge and the barristers and the jury
should undergo an elementary course of chemistry before
they took part in the trial of a reputed poisoner ? They
have only to weigh the testimony of professional witnesses,
and to give, as far as possible, a verdict in accordance
with that judgment which is a common attribute of
mankind.
In conclusion, it might be said that Natural Selection
has passed beyond the range of discussion, in that it has
met with universal acceptance on the part of all persons
competent to pass a judgment in the matter. But even
in that case, discussion might still do good. Mr. John
Stuart Mill says, in his Essay On Liberty:—
“ However true an opinion may be, if it is not fully, frequently,
and fearlessly discussed, it will be held as a dead dogma, not a
living truth. . . . This is not the way in which truth ought
to be held by a rational being. This is not knowing the truth.
Truth thus held is but one superstition the more, accidentally
clinging to the words that enunciate truth.”—(People's Edition,
p. 20.)
The same writer goes on to say that heretical opinions
are generally useful as a corrective of popular opinions.
“ Popular opinions on subjects not palpable to sense are often
true, but seldom or never the whole truth. They are a part of the
truth ; sometimes a greater, sometimes a smaller part ; but ex
aggerated, distorted and disjoined from the truths with which they
ought to be accompanied and limited. Heretical opinions, on the
other hand, are generally some of these suppressed and neglected
truths, bursting the bonds which kept them down, and either seek
ing reconciliation with the truth contained in the common opinion,
or fronting it as enemies and setting themselves up with similar
