s,
which from the multitude of facts embraced can only be verified by
prolonged and intricate inquiry. Attempts at the explanation of the
smallest phenomena proceed on the same plan, and the verification
of conjectures about them is subject to the same conditions, and the
methods of investigation and the conditions of verification can be
studied most simply in the smaller cases. Further, I venture to think
it a mistake to confine ourselves to scientific inquiry in the narrow
sense, meaning thereby inquiry conducted within the pale of the
exact sciences. For not merely the exact sciences but all men in the
ordinary affairs of life must follow the same methods or at least
observe the same principles and conditions, in any satisfactory
attempt to explain.

Tares appear among the wheat. Good seed was sown: whence, then, come
the tares? "An enemy has done this." If an enemy has actually been
observed sowing the tares, his agency can be proved by descriptive
testimony. But if he has not been seen in the act, we must resort to
what is known in Courts of Law as circumstantial evidence. This is the
"hypothetical method" of science. That the tares are the work of an
enemy is a hypothesis: we examine all the circumstances of the case in
order to prove, by inference from our knowledge of similar cases,
that thus, and thus only, can those circumstances be accounted for.
Similarly, when a question is raised as to the authorship of an
anonymous book. We first search for a clue by carefully noting the
diction, the structure of the sentences, the character and sources of
the illustration, the special tracks of thought. We proceed upon the
knowledge that every author has characteristic turns of phrase and
imagery and favourite veins of thought, and we look out for such
internal evidence of authorship in the work before us. Special
knowledge and acumen may enable us to detect the authorship at once
from the general resemblance to known work. But if we would have clear
proof, we must show that the resemblance extends to all the details of
phrase, structure and imagery: we must show that our hypothesis of the
authorship of XYZ explains all the circumstances. And even this is
not sufficient, as many erroneous guesses from internal evidence
may convince us. We must establish further that there is no other
reasonable way of accounting for the matter and manner of the book;
for example, that it is not the work of an imitator. An imitator may