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IV. The
Directing Principles of Knowledge
Topics:
- A. General notion of the directing
principles of knowledge
- B. Origin and nature of these
principles
- C. Logical and real value
A. General notion of
the directing principles of
knowledge
Our knowledge consists of judgments, connected
and coordinated with one another. The progressive
life of the mind moves by a regular process in
which judgments are built upon other judgments, so
that the judgment is the principal and central act
of the mind (II, D). Amongst these mental
enunciations there are some which play a capital
role in the life of the mind. They rule not only
its psychological development, but also its
epistemological and logical functioning, and
therefore they deserve our special attention. We
call them the directing principles of knowledge. To
this class belong
- the principle of contradiction (a thing
cannot both be and not be);
- the principle of identity (that which is,
is; being is equal to itself);
- the principle excluded middle (there is no
middle term between being and non-being);
- the principle of sufficient reason (being is
endowed with all the elements without which it
could not be);
- the principle of totality (the whole is
equal to the sum of its parts);
- the principle of efficient causality
(non-necessary being exists by the influence of
a being other than itself).
There are many others. All form one long series,
in close connection with the principle of
contradiction, of which they all express different
elementary phases or applications.
These judgments are called
principles because they serve as a
basis for other judgments:
- first or immediate principles,
because it is impossible to prove them by
reference to more fundamental judgments;
- directing principles (axioms
or axiomata in the language of the
Schoolmen) because they express simple relations
between being, of whatever kind it may be, and
certain elementary and primordial notions which
are connected with being, such a 'non-being,'
'whole,' 'part,' 'commencement of
existence.'
B. Origin and nature of
these principles
We may say that experience is the
source of these principles, in the
sense that the ideas which form the subject and
predicates of the judgment are derived from
experience. 'Being,' 'whole,' 'commencement of
existence,' 'causality,' are derived from the
matter of our internal and external sensations, by
way of abstraction. We may go farther and say that
experience facilitates the
enunciation of the relation between the subject and
predicate. For instance, I enunciate the principle
of contradiction in realizing that I cannot be in
the lecture hall and in the dark room at the same
time; and the principle of causality, in realizing
that my arm is raised by the command of my will
acting as a cause.
But it is of vital importance to note that for
the Schoolmen the bond of union
established between the subject and predicate of
the first principles we are considering is based,
not upon experience, but upon the content of the
subject and predicate, as revealed by mere
analysis. When I say A = A, this judgment results
from the mere consideration of A (whatever it may
be) and not from experience. Since it does not
depend upon human experience, which attains only to
what actually exists, the bond of
union expressed by these principles is therefore
independent of the existence of the present
universe, and, in fact, of all creation. Their
validity does not depend on the
condition that something exists: it
is absolute. If the universe had never existed, and
there was just one intelligence besides God, this
would have been capable of knowing the axioms which
govern human knowledge. The idea of being, and the
other primordial notions correlative to it, could
be obtained by such an intelligence from its
knowledge of itself, or from God, and the
juxtaposition of subject and predicate is
sufficient to reveal the relation between them in
the case of the axioms in question.
This supposition shows that there is no
contradiction between the view expressed earlier
that the constituent ideas of these principles
(being, non-being, totality, etc.) are abstracted
by the mind from external or internal sense
perceptions, and this other view that the bond
uniting these contents may be grasped without the
aid of experience.
By reason of these characteristics, directing
principles or axioms belong to a comprehensive
class of judgments which are said to be 'knowable
as a result of the mere juxtaposition of the terms'
subject and predicate (propositio per se
nota) and which would be called today judgments
of the ideal order.
This class of judgments is opposed to a second
category, which we need not study here, but which
we mention only in order to emphasize the nature of
the directing principles which we are now
considering. In this second category of judgments,
it no longer suffices to juxtapose the term in
order to see the relation between them: we must
have resource in addition to experience
(propositio per aliud nota; the aliud
is experience). If I do not need to subject my
judgment to the control of experience in order to
know that being and non-being are mutually
exclusive, this control is indispensable in the
case of the judgment that water boils at 100
degrees C.; or that men have a natural tendency to
live in social groups. The second class of
judgments would be known today as judgments of the
existential order (XVI, B).
Let us consider more closely the group of
judgments to which our directing principles belong.
It would appear at first sight that the judgment of
the ideal order of the Schoolmen coincides with the
'judgment de jure' of Leibnitz, and
the 'analytic' judgment of Kant, i.e., the judgment
in which the subject includes the predicate. It is
true that scholastic philosophy classifies among
judgments of the ideal order these propositions,
which Kant despised as mere tautologies. But Thomas
Aquinas goes on to point out that there is another
kind of judgments of the ideal order, knowable by
the mere analysis of the subject and the predicate,
and which is much more interesting. In these the
predicate is not included in the
subject, but nevertheless a clear knowledge or
insight into the predicate reveals the bond which
indissolubly unites it with the subject, once this
subject is give. Although the predicate is not
contained within the subject, there is an
exigentia, or need, which imperiously
demands the union of predicate and subject. The
axioms which we are considering in this part all
belong to this second class, except perhaps the
principle of identity.
Take, for instance, the principles of
contradiction and that of causality. The mere
analysis of the notion of being will never reveal
the notion of non-being (the negation is not
implied in the affirmation), nor that of
incompatibility with (the relation
with is not implied in the notion of
a thing considered in itself). But once the ideas
of being and non-being are present to a mind the
incompatibility of the two is forcibly evident. Or
again, from the notion of 'non-necessary existence'
we could never deduce that of 'actual existence in
the realm of fact.' But if we juxtapose and compare
the two notions, it is evident to us at once that
the one is not the other, and that if a
non-necessary thing is conceived as existing in
point of fact we cannot explain this existence,
without something other than itself. Indeed, a
non-necessary thing is non-existent of itself.
Hence, it cannot give to itself what it does not
possess. As soon as this non-necessary being is
represented as existing, it ought to be referred to
some external influence -- a causal
influence -- which is the sufficient reason of this
existence. This is the enunciation of the principle
of efficient causality: "The existence of a
non-necessary being demands a cause."
C. Logical and real
value
Since the relation which unites the terms of the
directing principles is so evident that 'leaps to
the eyes' as the French say (sauter aux
yeux), independently of experience, and since
these principles express the laws of being as such
and of all being, there will be no difficulty in
allowing that they govern all
conceivable being. They direct and
control every assertion; they rule 'universal
intelligibility.' They therefore rule and guide the
collection of judgments which go to make up our
human sciences, and likewise the various judgments
which regulate our practical life. For instance, if
the principle of contradiction were to become
uncertain, or doubtful, no human
affirmation would hold good, -- not
even the famous dictum, "I think, therefore I
exist." The assertion of my existence is not valid,
if what I perceive as real can both be and not be.
For this reason the principle of contradiction is
called by the Schoolmen the first principle
par excellence, and they make their
own the declaration of Aristotle to the effect that
a person who could not grasp this principle would
not be a man, but a blockhead.
Do these principles, which apply to all
conceivable beings, also govern
existent being, in case anything is
proved to exist? And if they govern the material
universe as a whole, will they apply also to a
world of suprasensible or spiritual beings, if such
exist? These questions form part of the great
epistemological problem which we must now
consider.
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