METHOD OF PROOF.
In a matter of scientific inquiry one cannot go far wrong if one
follows the advice of Henri Poincaré, who lays down certain principles
of method; four of these are the following:--
(1) The most interesting facts are those which can be used several
times, those which have a chance of recurring.
(2) The facts which have a chance of recurring are simple facts.
(3) Method is the selection of facts, and accordingly our first care
must be to devise a method.
(4) We should look for the cases in which the rule established stands
the best chance of being found fault with.
The groups of facts described in the succeeding chapters are in
agreement with these principles in the main, and are perhaps like a
dust heap for their intrinsic value. But one knows that before now
among a good deal of _débris_ a rusty key has been found which has
opened a cabinet containing certain treasures, and in the hands of
someone else than the finder has produced useful results.
The headings of the chapters describe the facts, and there is no
need to enumerate them here. The first and largest group is studied
according to a method which is in a measure applied to all the others.
Most of them are external or superficial phenomena and accordingly are
open to others beside the expert for observation and corroboration, or
the reverse. The typical plan adopted is as follows: a large number
of related phenomena are chosen, and the more prominent of these are
observed and described. Keeping in mind the two plain issues laid down,
the origin of initial modifications and their transmission, I have
selected the facts because, especially such as those of the hair, they
are very simple, of wide distribution in animals well known to us,
such as the domestic horse and man, and none are brought forward which
any other observer cannot study for himself if he has some anatomical
and physiological knowledge, some training and care in recording
observations. In most centres of population there are still left a good
supply of horses in streets and stables, of preserved specimens in
museums and living ones in zoological gardens, and of hairy young men
who will hardly refuse a polite request to examine the minute hairs
clothing their trunks and limbs. One has to pursue a certain amount
of that study which may be called the sister of plant-ecology, that
is, animal-ecology or the behaviour of animals at home. The student of
these matters, it may be freely admitted, will complain, unless he has
some hypothesis or line of thought to follow, that he has been set down
in a valley in which the bones are very many and very dry. But, armed
or primed with an hypothesis, he may find an affirmative answer to his
question “Can these bones live?” Every group of natural phenomena,
_without exception_, has some meaning for those who will interpret
nature rather than bully and slight her, and whatever anointed king
may claim sovereignty over it the humble fact cannot be denied that
“whatever phenomenon is, _is_.”[40] Again I would refer to Howes’
inspiring note: “We live by ideas; we advance by a knowledge of the
facts; content to discover the meaning of phenomena, since the nature
of things will be for ever beyond our grasp.”[41] The facts adduced
are simple, have a chance of recurring and are widely distributed
among multicellular animals--the botanists and plants can very well
take care of themselves. I must once more state that I am attaching
to the considered facts a value of a somewhat unusual kind--_their
intrinsic unimportance_. For anyone who has had to encounter the
skilful dialectics and counter-attacks of a well-equipped neo-Darwinian
it is well that he should remember the maxim of Napoleon, “Be
vulnerable nowhere.” It is necessary to show evidence for Lamarckian
factors in which no degree of selective value, survival-value, can
be seen by hostile sharp-shooter while he works in his trench. The
main line of defence, or more correctly what Hindenburg would call
“offensive-defence,” is therefore made to rest on the phenomena of
hair-direction, which, I submit, are impregnable to the forces of
selection, probably in all the hairy mammals, but certainly in that
hairy animal called Man.
[40] Jevons.
[41] British Association of Science 1902. Zoological Section.
Thesis.
If these groups of phenomena were being studied apart from the
hypothesis they support, a much more full treatment of all of them
would be required, such as I have given to those of hair-direction in
a book published in 1903 on _Direction of Hair in Animals and Man_.
The limited thesis, however, here upheld is that the phenomena are
produced by the factors of stimuli and response in the course of
the total experience of the organism, that the essence of the matter
is the production of initial modifications, that instances of these
in well-known animals are produced before our eyes by ascertainable
mechanical stimuli, and that, especially in those of hair-direction,
experiment is adduced in proof of the thesis that some modifications
are transmitted.
Procedure.
The order of proceedings may be tabulated thus:--
(1) Observation of selected facts.
(2) Evidence that certain of these are produced in the lifetime of
the individual.
(3) Evidence that among the facts of direction of hair and others
there is to be seen an orderly evolution rather than a casual
appearance of the changes noted.
(4) An hypothesis as to their production.
(5) Exclusion of selection as a possible cause of these, and of
correlation as properly understood.
(6) Experiment in verification of the Lamarckian interpretation of
the phenomena.
And here, before I hear some Prince Henry of the genus Weismann, Mendel
or Gallio groan aloud: “This intolerable amount of sack,” I proceed to
offer him a few loaves of home-made bread.