From
The Journal of Philosophy, Vol. 26, No. 14, July 4, 1929, 379-384.
“[T]he pursuit of meaning is philo-sophy.”
Posted June 9, 2009
The Treadmill of
Systematic Doubt
Susanne K. Langer
The true philosopher, we are often told, doubts everything that can not
be proved from absolutely sure premises. Philosophy begins with doubt,
usually about some theological or moral propositions that have so far
held the rank of beliefs; if it is system-atically pursued, it will lead
the devotee to doubt, in turn, the existence of consciousness, of space,
of re-lations, of logic, of the external world, and of other people’s
minds; and this skepticism is supposed to clear the way for true
knowledge.
But in the shrine of pure reason, now so pure as to be empty, we find
one new doctrine as easy to set up as another; we can prove to our own
satisfaction, according to our inclinations, the complete certainty of
Spirit, or Matter, or logical Categories, Monads, Egos, Essences, Vital
Urges, or the Absolute; but the most convincing proof of our realities
will not prevent the next person from doubting the whole product, going
through the same mental acrobatics of skep-ticism and introspection and
proof, and arriving at very different results. Every thinker must begin
at the beginning not only of his specific problem, but of the whole
field of knowledge. And as the collection of weird entities increases,
the business of clearing the way becomes more and more irksome, for
there are more and more things whose existence must be refuted.
Everything must be doubted that possibly can be; and the really honest
scholar, realizing that every philosopher before him has been
discredited by many competent persons, becomes wary, in the end, about
believing anything, for he is no longer satisfied with the
“self-evidence” of his assumptions. He re-futes his own ideas, and
finally is faced with a choice between blind dogmatic beliefs, or no
beliefs at all—between skepticism, or animal faith.
The one thing he probably never has doubted is the virtue of systematic
doubt. It is a truism that any existential proposition may be false.
But this does not preclude the possibility of a proposition’s being
necessary in a certain universe of discourse, namely, a proposition
which states the essential concepts, the terms and relations, which
compose that uni-verse. Out of these all our propositions are
com-pounded; and these basic concepts, quite apart from any dogmas
concerning their metaphysical “reality” or “existence,” are our
premises.
Therein lies the force of a dictum like Descartes’ “I think.” It
presupposes the thinker. Hence “I do not think” would be an
abbreviated statement meaning really, “I think that I do not think.”
The notion of thinking is initially given in the assumption of “me, the
thinker.” Of course, Descartes was not aware of that presupposition.
Within any system, there are these notions which are being used,
hence can not be denied without throwing the whole universe of dis-course
into utter chaos. Such a basic notion is think-ing (cogitare) in
Descartes; and whenever we are not aware of the fact that we reason with
presupposed terms (as, of course, we always do), propositions which
assert them seem “self-evident.” But herein also lies the reason that
there is probably no proposition that will always appear self-evident to
all people.
We might say, then, that it is impossible to doubt the notions we are
using; and that consequently phil-osophers who set out to establish the
“truth” of their premises are always driven back from terms and
relations they have just caught themselves using, to unavowed new ones
wherewith to attack the old. Thus they run from pillar to post—and just
that, in the last analysis, is the process of systematic doubt.
It is bootless to doubt your premises. You can only make a bow of
recognition, unless you are ready to dispense with them and start over
again with a new set. For when we doubt a proposition, we are still
thinking in its terms, and where the proposition is the establishment of
these very terms, as Descartes’ “Cogito,” this commits us to a vicious
circle of the type ψ(ψx). Given the postulates which establish your
universe of discourse, you may doubt any other proposition in their
terms, because it is just one of the many possible combinations, and if
your pre-mises are good, then there is a correct formulation for every
theorem; but you can not doubt your con-cepts—you can only show, by the
Cartesian criterion of self-evidence, if you like, that they are
your basic concepts.
Descartes has been characterized as “the father of all evil in modern
philosophy”; this designation was provoked chiefly by his division of
the world into matter and mind, but it might as well have been inspired
by his methodology. For his dualism has wrought havoc in metaphysics,
but his systematic doubt has done worse—it has thrown our standards of
knowledge into confusion. It has turned the human mind from its native
desire for intelligibility to a craving for absolute truth.
The scholastics had faith in reason, because they demanded of it merely
that it should make things reasonable. They did not ask it to give
special sanctions to its premises. Such guar-antees were contained in
the very language of the Church. The Greek thinkers, too, had held no
ideal of knowledge beyond the rationalization of experience—they did not
question their basic concepts, because these were the unconscious
assumptions of common sense. But Descartes proposes to doubt
everything that has not the stamp of Absolute Truth.
This challenge has led to impossible epistemo-logies, and metaphysical
doctrines that would raise themselves by their boot-straps; attempts to
see the world from all points of view, or from no point of view;
but above all, it has given rise to a psychological need which is
peculiar to our epoch, and may truly be called the Spirit of Modern
Philosophy—our need of personal convictions.
Before Descartes, people reasoned from propo-sitions which no one,
educated or other, saw any oc-casion to question. Their premises were
habitual assumptions, with the stability and dignity of all unconscious
tradition—the warp and woof of their world, and as certain as the world
itself. And the results, of course, would be as convincing as the
reasoning seemed to be good. Once in a great while, a brilliant
thinker, faced with some insolubilium, would unearth a false
premise of common sense, as Leonardo and Galileo occasionally did; but
he would not tamper with common sense beyond the require-ments of his
problem. Doubt of an old assumption was contained in the dawning of a
new one; it would hardly have been considered as a separate step in the
logical process. And naturally it was the new idea, not the old one,
whose fate was interesting. The discarded one automatically dropped out
of sight. No one inquired for its health after that, no one who could
appreciate the new conception ever regretted the old.
But now we find people distressed at the thought that there can be wrong
premises, and demanding credentials before they will accept any notions
at all. Any term that is used must first be thought to “exist.” And
since most of us have outgrown the naïve faith that accepted the
“self-evidence” of certain propositions as a proof of their truth, we
have had to take recourse to such sad makeshifts as a “Will to Believe,”
or failing that, a philosophy of “As If.” But in truth, this sort of
belief is really a peculiar psychological attitude, a feeling, rather
than an im-provement upon our knowledge. People can attach most
vehement sentiments of belief to statements which, upon analysis, are
found to have no meaning whatsoever. They can believe in a “First
Cause,” in “the Infinite where all paths meet,” in mysteries of every
sort; the duchess in Wonderland is not the only person who, with a
little practice, can believe as many as six impossible things before
breakfast. Philosophers and laymen alike have done so well as to believe
any number of impossible things, not only before breakfast, but all the
time!
In other pursuits of the human reason, for in-stance in science or
mathematics, we simply use our basic formulations. When they are not in
use, they are not doubted, but forgotten; they are meaning-less. But in
philosophy we are forever looking them up and down and trying to prove
that they are “true.” This involves, of course, that other entities,
pre-viously “believed in,” must now be thought not to exist. Thus
begins a great contest of proof and refu-tation, for the establishment
of Universals or Atoms or Monads or Selves, and in the end we take our
choice more or less by personal predilection. If a philosopher says to
you: “I doubt the external world,” you expect him to disprove realism,
to prove that certain things you had always believed in do not really
exist, that they are illusory appearances, and the only things which are
real are the things inside your mind. But if a physicist says
“Space-time and its modifications are the ultimate physical realities,”
you do not expect him to refute the existence of material chairs and
tables, but to make some older notion of matter simply vacuous. Indeed,
you are not asked to “doubt matter”; you are merely asked to understand
the notion of Space-time.
That, we are sometimes told, is all very well for scientific inquiry,
but is contrary to the program of philosophy; the scientist does not
worry about his logical principles as long as he has good “working”
ideas, which lead him to the discovery of new facts, whereas the
philosopher has the ideas more at heart than their precise working.
There is some truth in that contention, but not as much as people
generally suppose. The scientist is, indeed, interested chiefly in
finding more and more exemplifications of his formal
propositions; and as the generic notions of a science like physics are
very powerful ones, the deductive and experimental work which is based
upon them keeps many generations of researchers busy; that is why, as
long as all goes well and the field of possible combinations and
observations is vast, there is little if any point in reconsidering the
premises. But as soon as there is an incomprehen-sible phenomenon, a
theorem which ought to follow and does not, the man of science has to
turn philoso-pher. He must review all his fundamental concep-tions. It
is noteworthy that the great physicists are the most ardent
metaphysicians. They say far more startling things than any idealist or
realist or prag-matist would dare to say. They doubt the three-di-mensionality
of the world, the conservation of mat-ter, the infinity of the universe,
with a matter-of-fact disregard of common sense that makes philosophers
sit down and gasp. But the remarkable feature of their theorizing is
that they never use systematic doubt. They look over their postulates,
and perhaps say to themselves, “Ah, there’s the rub; here’s the
contradiction.” And if reforming the postulates will not help the
situation, they go on to reflect whether with entirely different
terms a more adequate set could be constructed. They do not doubt
any facts, nor the existence of any familiar entities, but simply make a
different analysis of experience.
The fallacy which, I think, vitiates almost all of modern philosophy,
and which we owe in large mea-sure to the reputed father of that
subject, is the metaphysician’s tendency to treat concepts as entities.
I do not mean merely the mistake against which we have often enough
been warned, of hypo-statizing universals; I mean the subtler folly of
asking for the “existence” of a thing which answers to no precise
description, even for the “existence of any-thing,” and worrying about
the truth or falsehood of a proposition instead of asking what is its
sense. William James’s question, “Does Consciousness exist?” is a good
case in point. What he should have asked, is, “Can we talk coherently
about ‘conscious-ness’?” For consciousness is not a thing, that might
exist; it is a concept, which either can or can not be used in
describing a certain kind of experience. If we apply the pragmatic
criterion to concepts instead of propositions, it seems to me perfectly
unassailable.
The function of philosophy is not to doubt every-thing, and then prove
the existence of things; it is to assume as little as possible, and
understand as much as possible. Thus its interest centers in
concepts, which are the instruments of understanding, and not in
entities; and its proper method is not Cartesian, but, in a somewhat
broadened sense, Socratic. It can never profitably begin with doubt,
because doubt is a complicated psychological attitude, which, like
belief, has nothing to do with insight or knowledge, but may attach to
nonsensical formulæ as well as to real propositions. Philosophy should
begin not by denying something (let alone everything!), but by
saying something: preferably something reasonably simple and concise.
Not any and every arbitrary pro-position will furnish a good
starting-point. A meta-physical formulation should always be made with
some ulterior motive—not to explain the world, for that is meaningless,
but to describe some definite aspect of experience. It is useless to
introduce a conception of Mind without any reference to its
psy-chological uses, or to talk about Matter without intending to
clarify the field of pure physics. If we would make intelligible a set
of terms to describe our world, we must have an eye to the details of
such de-scription. Then, having said something that sounds promising,
such as that “the modifications of Space-time are the ultimate physical
realities,” we may reflect upon the conceptual content of that premise,
and interpret the words until they make sense. That sort of reflection
may be neither necessary nor interesting to the scientist, except at
certain crucial times, but it is the whole concern of the philosopher,
because he is in search of meanings, not of facts: the pursuit of
meaning is philosophy.