3 - The Problem of Human Knowing:
A Historical Overview
From The Philosophy of the Human Person, by James B. Reichmann, SJ
. . . it is not impossible to become a competent
scientist without knowing much about the history
of science, but no man can carry very far his
own philosophical reflections unless he first
studies the history of philosophy.
Etienne Gilson
INTRODUCTION
The problem of human knowing is central to the problem of what it means to be human.
It is not surprising, therefore, that the problem of knowing has played an important role in
the historical development of Western philosophy. How this problem is resolved does,
to a high degree, shape and determine one's view regarding a philosophy of the human
person. A historical overview, however brief and inadequate, will greatly facilitate our
understanding of the positions taken by modern and contemporary philosophers. It will,
as well, enable us to contrast somewhat the views assumed by more recent thinkers with
those of the early Greek philosophers, pointing up the similarities and differences
between the two as well as highlighting areas of historical dependence.
PLATO (427-347 B.C.)
Plato was the first philosopher to undertake an in-depth analysis of the phenomenon of
human knowing. He is without question one of the great intellectual geniuses of the
Western world. Indeed, many scholars would rank him at the top.
Unfortunately, since all of the major extant works of Plato are in dialogue form, it is
difficult to determine whether or not the views expressed in the dialogues are meant to
represent Plato's own views. Therefore, I will make no pretense of presenting an
authentic historical account of Plato's views, but instead will provide a brief summary of
the theory of forms, which seems to have its historical origin with Plato himself. We must
leave to the Platonic scholar the ultimate determination of what Plato's own position was
with regard to his theory and, particularly, whether he might have changed his views
toward the end of his life.
Scholars remain divided regarding the definitive interpretation of Plato's theory of
recollection, and it may well be that the outstanding historical questions surrounding his
views may never be resolved to everyone's satisfaction. For purposes of our present study
we assume nothing more than that Plato intended his theory of forms to be taken
seriously.
Plato, who was deeply convinced of the intellectual dimension of man, made a sharp
distinction between sensory and intellective knowledge. He did not accept the teaching of
some of the earlier pre-Socratics, such as Democritus (460-362? B.C.), who viewed all
knowledge as essentially one and explained human understanding as merely a refined
form of sensation. Democritus conceived of knowledge as an effect of impinging atoms,
from which all material things were made, on the senses. To explain the phenomenon
of knowledge, Democritus employs what today we would call a mechanistic model,
which is based on the assumption that ideas are merely images formed by the patterned
onslaught of small particles of matter on the sensory faculties. In short, Democritus
assumes a materialist position and sees no fundamental difference in sensing, knowing,
and other activities found in nature, such as growth. Further, Democritus is a subjectivist,
or phenomenalist, since he also maintains that what we know are the images, or
perceptions, within the senses, not the things themselves, independent of the knower.
Plato reacts forcibly against such a view of human knowing, and the general thrust of all
his dialogues is to insist on the transcendent dimension of the human spirit vis-a-vis the
material world. In his concern to refute the materialism of the earlier philosophers, Plato
tends to sharply divide the world of human experience into two domains: that of
understanding and that of sensory perception.
Plato is convinced that the human act of understanding involves an activity that totally
transcends the world of material objects and sensation. Ideas are universal and abstract
and are unlimited by time and space. Consequently, Plato does not see how they could
derive from the shadowy world of sense objects where things are in continual flux and
are singular, material, and limited; therefore, subject to the limitations of time and space.
Because of the dichotomy between the intellective and the sensory worlds, Plato saw no
possibility for any real interaction between them, at least not to the extent that the mind is
dependent upon the world of material things for the ideas it has. Since ideas are universal
and immaterial, they could not derive from the material world where everything is
singular. This leads Plato to deny that the material world is truly a cause of our
knowledge. He will not deny, however, that the world of sensible things plays a role in
our knowing, for it does occasion our awareness of our ideas. Yet Plato does not admit
that the material world causes that knowledge, and thus he denies that there is any real
dependency of the mind on sensible, or material, things. Hence, he must look elsewhere
for his explanation of the origin of the ideas found in the human mind.
In order to account for the ideas we have, Plato appeals to a prior existence of the mind or
soul. He suggests that prior to birth the soul enjoyed a fullness of knowledge but that,
when it was conjoined with the body, the soul lost its conscious awareness of the ideas it
once had. Since union with the body induces in the soul a general state of forgetfulness, it
is the role of sensible things to stimulate and thus occasion our recollection of the ideas
we possess in our subconscious. It is for this reason that Plato is able to say that all
learning is merely a matter of remembering and that, consequently, knowledge
leads one back to the world of prior existence, where the mind or soul enjoyed an
uninhibited vision of truth and goodness, of the ideas it now must struggle to recall
through its contact with, and immersion in, the material world, which is really a world of
shadows.
From this, one can readily see that Plato's theory of the origin of knowledge is heavily
intellectualist and that it attributes minimal importance to the body and to the world of
sensible forms. Indeed, Plato views the body as an obstacle to the life of the soul, a kind
of prison from which the soul is constantly trying to escape through the acquisition of
knowledge. This view is strongly reinforced by Plato's symbolic account of human
existence as it is presented in his famous allegory of the cave, in book seven of his
Republic.
ARISTOTLE (384-322 B.C.)
A pupil of Plato's for nearly twenty years, Aristotle understood Plato's teaching
thoroughly, but while he greatly admired his mentor, he was unable to entirely accept
Plato's teaching. It should be borne in mind that even though Aristotle's theory of
knowledge differs rather substantially from that of Plato's, Aristotle borrows heavily
from him and is, in many respects, very much a Platonist.
Aristotle shares Plato's profound conviction regarding the difference between sensory and
intellective activity. He agrees that ideas do in fact transcend the material world of
sensible things. Yet, at the same time, he does not accept Plato's contention that these
ideas are obtained through a prior existence. Rather, he maintains that all ideas in the
mind are derived through experience. Thus he views the material world as the cause of
our ideas and not merely the occasion of them.
In order to make good on this assertion, Aristotle must show how it is possible for
immaterial and abstract ideas to derive from material and concrete things. It is not an easy
task, and most of Aristotle's philosophic efforts, as well as those of many of the great
philosophers throughout the Western tradition, were directed either toward making such
an assertion plausible or toward attempting to show what an impossible task it was.
Briefly, Aristotle's rejoinder to Plato is as follows: All human knowledge is obtained
through experience. In the beginning of an individual's life, the mind is like a slate upon
which nothing is written. The body must thus share with the soul the task of accumulating
knowledge. The body is not the prison of the soul but the instrument whereby it obtains
access to the material world. All knowledge must, for Aristotle, come to the mind by
having in some way previously passed through the senses. To render such an explanation
consistent, Aristotle must view the sensible world, which for Plato is merely a world of
shadows, as a world of genuine intelligible objects. The material world was not actually
knowing but it was capable of being known; it was intelligible. Aristotle refers to it
simply as potentially knowable. The world is intelligible because, in a restricted but real
sense, it contains ideas embedded in sensible objects. These ideas or forms, as he calls
them, are not actually intelligible because they exist under material conditions, rather
the freeing of the material forms from their material conditions renders them actually
intelligible.
Thus Aristotle sees understanding as an act by which the mind becomes one with the
other, the material object. Not in the sense, of course, that there is a physical unity of the
two, for the stone does not truly enter either into the eye or into the mind, but in the sense
that the form or intelligible dimension of the material thing has been assimilated by the
mind, and now functions as the form or determining principle by which the mind has
been moved from a state of capacity to one of act. The mind is in act—that is to say,
actually knowing at this moment—to the extent that it is informed by the other. From
Aristotle's point of view, understanding is not remembering but discovering, for it is
through understanding that the other reveals itself to the mind. Clearly, then, according to
this view, the mind very much depends on the material world, not merely to occasion
what it knows but to cause it to actually be that which is known. Aristotle also speaks of
an agent, or active, intellect which performs the singularly important function of raising
the material thing to the level of pure intelligibility. That is, the role of the active intellect
is not to change the thing but to dematerialize it, liberating its form from the material
conditions which make it concrete, singular, and individual.
Aristotle's explanation places much more importance on the role of body in the human
knowing process than does Plato's. In Aristotle there is a marked shift away from an
appeal to an otherworldliness to explain knowing, and a pervading dependency of the
human mind or spirit upon the body and the world of material things. Yet, at the same
time, Aristotle also maintains that the act of understanding is an immaterial operation
which transcends the world of sense, even though it does take its rise from that world as
regards the content of its thinking. For Aristotle, human understanding is a dialogue with
the world of sensible things.