Of the two parts of this paper the first is a study in formal analysis.
It attempts to show that there is no problem, logically speaking, of
the existence of an external world. Its point is to show that the very
attempt to state the problem involves a self-contradiction: that the
terms cannot be stated so as to generate a problem without assuming
what is professedly brought into question. The second part is a summary
endeavor to state the actual question which has given rise to the
unreal problem and the conditions which have led to its being
misconstrued. So far as subject-matter is concerned, it supplements the
first part; but the argument of the first part in no way depends upon
anything said in the second. The latter may be false and its falsity
have no implications for the first.
I
There are many ways of stating the problem of the existence of an
external world. I shall make that of Mr. Bertrand Russell the basis of
my examinations, as it is set forth in his recent book _Our Knowledge
of the External World as a Field for Scientific Method in Philosophy_.
I do this both because his statement is one recently made in a book
of commanding importance, and because it seems to me to be a more
careful statement than most of those in vogue. If my point can be made
out for his statement, it will apply, a fortiori, to other statements.
Even if there be those to whom this does not seem to be the case, it
will be admitted that my analysis must begin somewhere. I cannot take
the space to repeat the analysis in application to differing modes of
statement with a view to showing that the method employed will yield
like results in all cases. But I take the liberty of throwing the
burden upon the reader and asking him to show cause why it does not so
apply.
After rejecting certain familiar formulations of the question because
they employ the not easily definable notions of the self and
independence, Mr. Russell makes the following formulation: Can we
"know that objects of sense ... exist at times when we are not
perceiving them?" (_op. cit._, p. 75). Or, in another mode of
statement: "Can the existence of anything other than our own[63] hard
data be inferred from the existence of those data?" (pp. 73 and 83).
I shall try to show that identification of the "data of sense" as the
sort of term which will generate the problem involves an affirmative
answer to the question--that it must have been answered in the
affirmative before the question can be asked. And this, I take it, is
to say that it is not a question at all. A point of departure may be
found in the following passage: "I think it must be admitted as
probable that the immediate objects of sense depend for their
existence upon physiological conditions in ourselves, and that, for
example, the colored surfaces which we see cease to exist when we shut
our eyes" (p. 64). I have not quoted the passage for the sake of
gaining an easy victory by pointing out that this statement involves
the existence of physiological conditions. For Mr. Russell himself
affirms that fact. As he points out, such arguments assume precisely
the "common sense world of stable objects" professedly put in doubt
(p. 85). My purpose is to ask what justification there is for calling
immediate data "objects of sense." Statements of this type always call
color visual, sound auditory, and so on. If it were merely a matter of
making certain admissions for the sake of being able to play a certain
game, there would be no objection. But if we are concerned with a
matter of serious analysis, one is bound to ask, Whence come these
adjectives? That color is visual in the sense of being an object of
vision is certainly admitted in the common-sense world, but this is
the world we have left. That color is visual is a proposition about
color and it is a proposition which color itself does not utter.
Visible or visual color is already a "synthetic" proposition, not a
term nor an analysis of a single term. That color is seen, or is
visible, I do not call in question; but I insist that fact already
assumes an answer to the question which Mr. Russell has put. It
presupposes existence beyond the color itself. To call the color a
"sensory" object involves another assumption of the same kind but even
more complex--involving, that is, even more existence beyond the
color.
I see no reply to this statement except to urge that the terms
"visual" and "sensory" as applied to the object are pieces of verbal
supererogation having no force in the statement. This supposititious
answer brings the matter to a focus. Is it possible to institute even
a preliminary disparaging contrast between immediate objects and a
world external to them unless the term "sensory" has a definite effect
upon the meaning assigned to immediate data or objects? Before taking
up this question I shall, however, call attention to another
implication of the passage quoted. It appears to be implied that
existence of color and "being seen" are equivalent terms. At all
events, in similar arguments the identification is frequently made.
But by description all that is required for the existence of color is
certain physiological conditions. They may be present and color exist
and yet not be seen. Things constantly act upon the optical apparatus
in a way which fulfils the conditions of the existence of color
without color being seen. This statement does not involve any dubious
psychology about an act of attention. I only mean that the argument
implies over and above the existence of color something called seeing
or perceiving--noting is perhaps a convenient neutral term. And this
clearly involves an assumption of something beyond the existence of
the datum--and this datum is by definition an external world. Without
this assumption the term "immediate" could not be introduced. Is the
_object_ immediate or is it the object of an immediate noting? If the
latter, then the hard datum already stands in connection with
something beyond itself.
And this brings us to a further point. The sense objects are
repeatedly spoken of as "known." For example: "It is obvious that
since the senses give knowledge of the latter kind [believed on their
own account, without the support of any outside evidence] the
immediate facts perceived by sight or touch or hearing do not need to
be proved by argument but are completely self-evident" (p. 68). Again,
they are spoken of as "facts of sense"[64] (p. 70), and as facts going
along, for knowledge, with the laws of logic (p. 72). I do not know
what belief or knowledge means here: nor do I understand what is meant
by a _fact_ being evidence for itself.[65] But obviously Mr. Russell
knows, and knows their application to the sense object. And here is a
further assumption of what, by definition, is a world external to the
datum. Again, we have assumed in getting a question stated just what
is professedly called into question. And the assumption is not made
the less simple in that Mr. Russell has defined belief as a case of a
triadic relation, and said that without the recognition of the
three-term relation the difference between perception and belief is
inexplicable (p. 50).
We come to the question passed over. Can such terms as "visual,"
"sensory," be neglected without modifying the force of the
question--that is, without affecting the implications which give it
the force of a problem? Can we "know that objects of sense, or very
similar objects, exist at times when we are not perceiving them?
Secondly, if this cannot be known, can we know that other objects,
inferable from objects of sense but not necessarily resembling them,
exist either when we are perceiving the objects of sense or at any
other time" (p. 75)?
I think a little reflection will make it clear that without the
limitation of the term "perceiving" by the term "sense" no _problem_
as to existence _at other times_ can possibly arise. For neither
(_a_) reference to time nor (_b_) limitation to a particular time is
given either in the fact of existence of color or of perceiving color.
Mr. Russell, for example, makes allusion to "a patch of color which is
momentarily seen" (p. 76). This is the sort of thing that may pass
without challenge in the common-sense world, but hardly in an analysis
which professes to call that world in question. Mr. Russell makes the
allusion in connection with discriminating between sensation as
signifying "the mental event of our being aware" and the sensation as
object of which we are aware--the sense object. He can hardly be
guilty, then, in the immediate context, of proceeding to identify the
momentariness of the event with the momentariness of the object. There
must be some grounds for assuming the temporal quality of the
object--and that "immediateness" belongs to it in any other way than
as an object of immediate seeing. What are these grounds?
How is it, moreover, that even the act of being aware is describable
as "momentary"? I know of no way of so identifying it except by
discovering that it is delimited in a time continuum. And if this be
the case, it is surely superfluous to bother about _inference_ to
"other times." They are assumed in stating the question--which thus
turns out again to be no question. It may be only a trivial matter
that Mr. Russell speaks of "that patch of color which is momentarily
seen when we _look at the table_" (p. 76, italics mine). I would not
attach undue importance to such phrases. But the frequency with which
they present themselves in discussions of this type suggests the
question whether as matter of fact "the patch of color" is not
determined by reference to an object--the table--and not vice versa.
As we shall see later, there is good ground for thinking that Mr.
Russell is really engaged, not in bringing into question the existence
of an object beyond the datum, but in _re_defining the nature of an
object, and that the reference to the patch of color as something more
primitive than the table is really relevant to this reconstruction of
traditional metaphysics. In other words, it is relevant to defining an
object as a constant correlation of variations in qualities, instead
of defining it as a substance in which attributes inhere--or a subject
of predicates.
_a_) If anything is an eternal essence, it is surely such a thing as
color taken by itself, as by definition it must be taken in the
statement of the question by Mr. Russell. Anything more simple,
timeless, and absolute than a red can hardly be thought of. One might
question the eternal character of the received statement of, say, the
law of gravitation on the ground that it is so complex that it may
depend upon conditions not yet discovered and the discovery of which
would involve an alteration in the statement. If 2 plus 2 equal 4 be
taken as an isolated statement, it might be conceived to depend upon
hidden conditions and to be alterable with them. But by conception we
are dealing in the case of the colored surface with an ultimate,
simple datum. It can have no implications beyond itself, no concealed
dependencies. How then can its existence, even if its perception be
but momentary, raise a question of "other times" at all?
_b_) Suppose a perceived blue surface to be replaced by a perceived
red surface--and it will be conceded that the change, or replacement,
is also perceived. There is still no ground for a belief in the
temporally limited duration of either the red or the blue surface.
Anything that leads to this conclusion would lead to the conclusion
that the number two ceases when we turn to think of an atom. There is
no way then of escaping the conclusion that the adjective "sense" in
the term "sense object" is not taken innocently. It is taken as
qualifying (for the purposes of statement of the problem) the nature
of the object. Aside from reference to the momentariness of the
_mental_ event--a reference which is expressly ruled out--there is no
way of introducing delimited temporal existence into the object save
by reference to one and the same object which is perceived at
different times to have different qualities. If the same
object--however object be defined--is perceived to be of one color at
one time and of another color at another time, then as a matter of
course the color-datum of either the earlier or later time is
identified as of transitory duration. But equally, of course, there is
no question of _inference_ to "other times." Other times have already
been used to describe, define, and delimit _this_ (brief) time. A
moderate amount of unbiased reflection will, I am confident, convince
anyone that apart from a reference to the same existence perduring
through different times while changing in _some_ respect, no temporal
delimitation of the existence of such a thing as sound or color can be
made. Even Plato never doubted the eternal nature of red; he only
argued from the fact that a _thing_ is red at one time and blue at
another to the unstable, and hence phenomenal, character of the
_thing_. Or, put in a different way, we can know that a red is a
momentary or transitory existence only if we know of other things
which determine its beginning and cessation.
Mr. Russell gives a specific illustration of what he takes to be the
correct way of stating the question in an account of what, in the
common-sense universe of discourse, would be termed walking around a
table. If we exclude considerations to which we have (apart from
assuming just the things which are doubtful) no right, the datum turns
out to be something to be stated as follows: "What is really known[66]
is a correlation of muscular and other bodily sensations with changes
in visual sensations" (p. 77). By "sensations" must be meant sensible
objects, not mental events. This statement repeats the point already
dealt with: "muscular," "visual," and "other bodily" are all terms
which are indispensable and which also assume the very thing
professedly brought into question: the external world as that was
defined. "Really known" assumes both noting and belief, with whatever
complex implications they may involve--implications which, for all
that appears to the contrary, may be indefinitely complex, and which,
by Mr. Russell's own statement, involve relationship to at least two
other terms besides the datum. But in addition there appears the new
term "correlation." I cannot avoid the conclusion that this term
involves an _explicit_ acknowledgment of the external world.
Note, in the first place, that the correlation in question is not
simple: it is threefold, being a correlation of correlations. The
"changes in visual sensations" (objects) must be correlated in a
temporal continuum; the "muscular and other bodily sensations"
(objects) must also constitute a connected series. One set of changes
belongs to the serial class "visual"; the other set to the serial
class "muscular." And these two classes sustain a point-to-point
correspondence to each other--they are correlated.
I am not raising the old question of how such complex correlations can
be said to be either "given" or "known" in sense, though it is worth a
passing notice that it was on account of this sort of phenomenon that
Kant postulated his threefold intellectual synthesis of apprehension,
reproduction, and recognition in conception; and that it is upon the
basis of necessity for such correlations that the rationalists have
always criticized sensationalist empiricism. Personally I agree that
temporal and spatial qualities are quite as much given in experience
as are particulars--in fact, as I have been trying to show,
particulars can be identified _as_ particulars only in a relational
complex. My point is rather (i) that any such given is already
precisely what is meant by the "world"; and (ii) that such a highly
specified correlation as Mr. Russell here sets forth is in no case a
psychological, or historical, primitive, but is a _logical_ primitive
arrived at by an analysis of an empirical complex.
(i) The statement involves the assumption of two temporal "spreads"
which, moreover, are determinately specified as to their constituent
elements and as to their order. And these sustain to each other a
correlation, element to element. The elements, moreover, are all
specifically qualitative and some of them, at least, are spatial. How
this differs from the external world of common-sense I am totally
unable to see. It may not be a very big external world, but having
begged a small external world, I do not see why one should be too
squeamish about extending it over the edges. The reply, I suppose, is
that this complex defined and ordered object is by conception the
object of a single perception, so that the question remains as to the
possibility of inferring from it to something beyond.[67] But the
reply only throws us back upon the point previously made. A particular
or single event of perceptual awareness can be _determined_ as to its
ingredients and structure only in a continuum of objects. That is, the
series of changes in color and shape can be determined as just such and
such an ordered series of specific elements, with a determinate
beginning and end, only in respect to a temporal continuum of things
anteceding and succeeding. Moreover, the determination involves an
analysis which disentangles qualities and shapes from contemporaneously
given objects which are irrelevant. In a word, Mr. Russell's object
already extends beyond itself; it already belongs to a larger world.
(ii) A sensible object which can be described as a correlation of an
ordered series of shapes and colors with an ordered series of muscular
and other bodily objects presents a definition of an object, not a
psychological datum. What is stated is the definition of an object, of
any object in the world. Barring ambiguities[68] in the terms
"muscular" and "bodily," it seems to be an excellent definition. But
good definition or poor, it states what a datum is _known_ to be as an
object in a known system; viz., definite correlations of specified and
ordered elements. As a definition, it is general. It is not made from
the standpoint of any particular percipient. It says: _If_ there be
any percipient at a specified position in a space continuum, _then_
the object may be perceived as such and such. And this implies that a
percipient at any _other_ position in the space continuum can deduce
from the known system of correlations just what the series of shapes
and colors will be from another position. For, as we have seen, the
correlation of the series of changes of shape assumes a spatial
continuum; hence one perspective projection may be correlated with
that of any position in the continuum.
I have no direct concern with Mr. Russell's solution of his problem.
But if the prior analysis is correct, one may anticipate in advance
that it will consist simply in making explicit the assumptions which
have tacitly been made in stating the problem--subject to the
conditions involved in failure to recognize that they have been made.
And I think an analytic reading of the solution will bear out the
following statement. His various "peculiar," "private" points of view
and their perspectives are nothing but names for the positions and
projectional perspectives of the ordinary space of the public worlds.
Their correlation by likeness is nothing but the explicit recognition
that they are all defined and located, from the start, in one common
spatial continuum. One quotation must suffice. "If two men are sitting
in a room, two somewhat similar worlds are perceived by them; if a
third man enters and sits between them, a third world, intermediate
between the two others, begins to be perceived" (pp. 87-88). Pray what
is this room and what defines the position (standpoint and
perspective) of the two men and the standpoint "intermediate" between
them? If the room and all the positions and perspectives which they
determine are only within, say, Mr. Russell's private world, that
private world is interestingly complex, but it gives only the original
problem over again, not a "solution" of it. It is a long way from
likenesses _within_ a private world to likenesses _between_ private
worlds. And if the worlds are all private, pray who judges their
likeness or unlikeness? This sort of thing makes one conclude that Mr.
Russell's actual procedure is the reverse of his professed one. He
really starts with one room as a spatial continuum within which
different positions and projections are determined, and which are
readily correlated with one another just because they are projections
from positions within one and the same space-room. Having employed
this, he, then, can assign different positions to different
percipients and institute a comparison between what each perceives and
pass upon the extent of the likeness which exists between them.
What is the bearing of this account upon the "empirical datum"? Just
this: The correlation of correlative series of changes which defines
the object of sense perception is in no sense an original historic or
psychologic datum. It signifies the result of an analysis of the usual
crude empirical data, and an analysis which is made possible only by a
very complex knowledge of the world. It marks not a primitive
psychologic datum but an outcome, a limit, of analysis of a vast
amount of empirical objects. The definition of an object as a
correlation of various subcorrelations of changes represents a great
advance--so it seems to me--over the definition of an object as a
number of adjectives stuck into a substantive; but it represents an
improved definition made possible by the advance of scientific
knowledge about the common-sense world. It is a definition not only
wholly independent of the context in which Mr. Russell arrives at it,
but is one which (once more and finally) assumes extensive and
accurate knowledge of just the world professedly called into question.