Mr. Charles S. Peirce’s article entitled “The Doctrine of Necessity
Examined,” which appeared in the last number of _The Monist_, must have
been a surprise to many thinking readers. It must have affected them in
a somewhat similar manner as Hume’s “Treatise of Human Nature” affected
Kant. It roused him from his dogmatic slumber: He abandoned dogmatism
but nevertheless did not accept Hume’s skepticism; he remained positive;
yet he propounded a better positive view than was the old dogmatism; he
established in philosophy the method of critique.
The parallelism between David Hume, who doubted the validity of our
conception of causation, and Mr. Charles S. Peirce who denies the
universality of the doctrine of necessity, is very marked in more than
one respect. It is, in spite of many differences, a case of close
analogy, and the answer which we shall have to give to either, will in
many respects be suited to both. Both shake the ultimate ground of
scientific research at its very root. Both call in question the most
fundamental concept upon which all our methods of investigation and
philosophy rest. Both challenge the reliability of an idea of which few
would hesitate to say that it is all but universally accepted. In fact
the ideas “causation” and “necessity” are more than kin. If analysed,
many of their elements will be found to be actually identical. Thus the
one cannot be either established or doubted without establishing or
doubting the other. Accordingly Mr. Peirce, in some respect, repeats
David Hume’s onslaught upon the current conception of the basis of human
knowledge with the more formidable weapons which a century of close
thought and scientific investigation have furnished him.
If Kant’s answer to Hume had been satisfactory, Mr. Peirce probably
would not have renewed the attack or he would have had to modify it
considerably. Kant, however, whom we both, Mr. Peirce as much as I
myself, admire as a master of philosophic thought, did not solve the
question satisfactorily. Yet Kant pointed out the way of solving it,
which was the middle way between dogmatism and scepticism, called by him
and his followers “Criticism,” and it is this way on which we trust is
safest travelling.
Mr. Peirce is right that the doctrine of necessity cannot be
“postulated,” for “to postulate a proposition is no more than to hope it
will be true.” The doctrine of necessity is, indeed, usually treated as
a postulate, and Mr. Peirce’s attack appears formidable because he shows
the weakness of the arguments which are commonly brought forward in its
favor and which we grant to be insufficient.
Mr. Peirce says (_The Monist_, II, 3, p. 330):
“In view of all these considerations, I do not believe that
anybody, not in a state of case-hardened ignorance respecting
the logic of science, can maintain that the precise and
universal conformity of facts to law is clearly proved, or even
rendered particularly probable, by any observations hitherto
made. In this way, the determined advocate of exact regularity
will soon find himself driven to _a priori_ reasons to support
his thesis. These received such a sockdologer from Stuart Mill
in his Examination of Hamilton, that holding to them now seems
to me to denote a high degree of imperviousness to reason; so
that I shall pass them by with little notice.”
Mr. Peirce is right when saying that necessitarianism must be founded
on something other than observation. Observation is _a posteriori_; it
has reference only to single facts, to particulars; yet the doctrine
of necessity, if there is anything in it at all, is of universal
application. The doctrine of necessity, let us not be afraid to pronounce
it clearly, is of an _a priori_ nature. The scientist assumes _a priori_,
i. e. even before he makes his observations or experiments, as a general
law applicable to every process which takes place, that, whatever
happens, happens of necessity in consequence of a cause and in conformity
to law, so that the same cause under the same circumstances will produce
the same effects. If all the _a priori_ reasons, as Mr. Peirce maintains,
received a sockdologer from Stuart Mill, then indeed we shall have to
abandon the idea of necessity as the superstition of a past and erroneous
philosophy and we shall have to start the world of science over again.
Mr. Peirce denies the strict regularity of natural law and introduces an
element of chance. He says (ibid. p. 336):
“To undertake to account for anything by saying boldly that it
is due to chance would, indeed, be futile. But this I do not
do. _I make use of chance chiefly to make room for a principle
of generalization, or tendency to form habits, which I hold
has produced all regularities._[73] The mechanical philosopher
leaves the whole specification of the world utterly unaccounted
for, which is pretty nearly as bad as to boldly attribute it to
chance. I attribute it altogether to chance, it is true, but
to chance in the form of a spontaneity which is to some degree
regular.”
Mr. Peirce is the pathfinder of a new and as yet untried road. He strikes
out boldly into the tumultuous ocean of chance, hoping to find in his
journey the connection between the East and the West, between contrasts
that seem to him otherwise unconnectible. The confidence of the bold
discoverer is set forth in the warnings he gives to all seafaring people.
He attempts to frighten the ill-informed minds who might innocently
venture out in other directions; and he will thus naturally prevent
many from falling either into the Charybdis of doubting the propriety
of applying the logic of probabilities to the problem of necessity
and causation in general, or, worse still, into the Scylla of the _a
priori_. The former, he tells us denotes “a state of case-hardened
ignorance respecting the logic of science,” the latter “a high degree of
imperviousness to reason.”
Mr. Peirce is well known as one of the keenest logicians now living.
Considering this fact I am slow to take up arms against him in defending
a case which he so strongly brands beforehand. I must from the beginning
plead guilty to a belief in necessity, and having critically revised
my view once more I cannot help upholding it. I am fully conscious of
the fact that hundreds, thousands, and millions of single experiences
(which in Kantian terminology are called _a posteriori_ arguments) cannot
establish a solid belief in necessity, nor can any imaginable number of
sequences prove the rigidity of causation, and I confess freely that I
support my thesis with _a priori_ reasons. Yet at the same time attention
must be called to the fact that neither Mr. Hamilton nor Mr. Mill had any
adequate conception of the _a priori_, and Mr. Mill’s sockdologer does
not disturb in the least the assurance of my view; for the _a priori_
can, in my opinion, be based upon the firm ground of experience.
All the many sense-experiences at our command, if considered singly,
cannot constitute knowledge. In order to weave the woof of the _a
posteriori_ into coherent cloth we want the warp of the _a priori_, and
I do not see how we can do without it. But the _a priori_ is not that
mystical hocus-pocus of absolute truth with its impertinent assumptions
such as it is presented by pseudo-Kantians and justly denounced by Mill;
it is not as Mr. Peirce brands it an “I cannot help believing,” it is
not a “natural belief,” nor is it as others conceive it an innate idea.
It is, briefly described, simply and solely formal knowledge, such as 2
× 2 = 4, to which we attribute universality and necessity and with the
assistance of which we are enabled to predict and predetermine certain
results beforehand (i. e. _a priori_). We might invent a new name for the
_a priori_, the latter having become odious through the denunciations of
its enemies and worse still, having been distorted beyond recognition
through the misuse to which it was put by its defenders and suppositional
friends. Yet that would be another question, and the idea of the _a
priori_, i. e. of formal knowledge involving universality and necessity
would remain the same.
The universality and necessity of formal knowledge are as a rule taken
for granted by scientists. But philosophy can take nothing for granted,
and the problem rises: How is the belief in the universality and
necessity of formal knowledge to be justified? Mr. Peirce’s onslaught on
the doctrine of necessity is a challenge to answer this question.