1 06. THE FACTS OF SENSE PERCEPTION.

 I. All men have

an invincible persuasion that certain objects appear to them, and

are perceived by them, as distinct from, and outside of, them

selves, and as endowed with certain features such as extension,

impenetrability, shape, colour, etc. This feeling of externality^-

of such objects has never been denied by even the most extreme

sceptics.

II. Hence, men spontaneously judge that outside themselves,

and independently of their conscious perceptions, there actually

exist real things endowed with such features and qualities. This

we may call the spontaneous judgment of externality or otherness.

It involves two sorts of judgment, the judgment of existence,

that a "reality or realities external to the perceiver exist," and

the judgment of nature, that " this reality is such and such,"

e.g. soft, spherical, cold, yellow, sweet, etc. ; that " this is an

orange," "that, is an oak," "that is a horse," etc., etc. That

men spontaneously make and believe such judgments is likewise

universally admitted.

III. Antecedently to philosophical reflection men spontane

ously believe that the existence of a real, external, material

universe, existing independently of their perception of it, is as

indubitably evident to them as their own individual existence.

Nay, when we want to express the strongest intellectual certi-

1 Some authors say that on reflection this feeling of externality can be indubit

ably detected only in the data of sight ; others only in the data of touch ; others only

in these two domains of data ; others in the data of hearing as well ; others even in

the data of taste and smell. Cf. JEANNIERE, op. cit., p. 385 n. All sensations

reveal objectivity of course ( 19). But not all reveal externality, e.g. the organic

sensations whereby we become aware of the internal states and conditions of our

bodies. Similarly, the feeling of volnmitiousness or extensity, which is held by some

psychologists to characterize the data of touch alone, is held by most to affect the

data of sight as well, and by many to affect in some measure the data of all the

senses. Cf. JEANNIERE, op. cit., p. 401, n. 2.

37

38 THEOR Y OF KNO WLEDGE

tude of the truth of any judgment we describe it in terms

borrowed from sense perception, we say that such a truth is

manifest^ as clear as noonday, palpable, that we see it, etc., etc.

It is admitted that so irresistibly does this persuasion of the

independent existence of an external universe force itself upon

men that even those cannot eradicate it, but continue to act on

it, who come to regard it as theoretically indefensible (37).

IV. We classify the conscious data or objects of sense per

ception into certain broad, clearly distinct and mutually irre

ducible domains : into colours, sounds, tastes, smells, organic

states (of bodily pleasure, pain, etc.), pressure, resistance to

muscular effort, heat and cold, size and shape, rest and motion,

position, location, number, etc. It is admitted by all that we

have such diversely qualified data or objects of sense awareness.

V. Even a moderate measure of reflection on the various

qualities which we thus apprehend in the " external " data of

sense awareness, and which we ascribe to things spontaneously

judged to exist outside us and independently of our perception,

will convince us that some of those qualities seem to be more

dependent than others, for what they appear to be, on the actual

condition of the bodily sense organs, 1 to be more relative than

others to the self as sentient subject. When, for instance, we

say that this stone is hard, this orange is round, this grass is

green, these clouds are moving ; and then that this water is

warm, this wine is mellow, this perfume is pleasing, we realize

that the former group of qualities belong to the subjects to which

we attribute them, more absolutely and independently of our

selves, than the latter group do to theirs : that what feels warm

to one hand may feel cold to the other, that the same "thing"

may not "taste " or " smell " the same to different people, or to

ourselves at different times, etc. This broad fact is undisputed ;

not so, however, its significance, or its application in detail.

VI. Reflection also reveals, among the qualities of sense data

or objects, another broad distinction which has been recognized

in one form or other at all times by students of sense perception :

1 Or, of the self as a corporeal, organic, conscious subject. The body, with its

sense organs, is apprehended by us in two distinct ways : (a) by our external senses

in the same way as we apprehend the " external " universe, and as similar to the

latter (corporeal, or material, extended, etc.) ; (b) by the internal, muscular, organic

senses, the functioning of which accompanies that of the external senses and con-

comitantly reveals the bodily organism as the sentient-conscious self or subject.

The former apprehension may be described as objective, the latter as subjective.

VALIDITY OF SENSE PERCEPTION 39

the distinction between what scholastics have called the " proper

sensibles " (sensibilia proprid} and the "common sensibles"

(sensibilia communia). The former are the concrete qualities, or

"qualified" data or objects, of each separate sense: colours,

sounds, tastes, odours, pressures or resistances, temperatures,

organic states. The latter are concrete, "qualified" data or ob

jects, apprehended in common or by more than one sense channel :

shape (forma vel figura), size or volume (inagnitudd], number

(inultitudd}?- rest, motion. The former are also called the

"secondary" sense qualities, and the latter the "primary" sense

qualities, of matter (or of "corporeal " or "sense" data).

This division of sense data into "primary" or "common,"

and "secondary" or "proper," is recognized as grounded in

consciously apprehended differences between the two sets of data

respectively. But its significance and implications are much dis

puted. The former or " common " sensibles are clearly all con

crete modes of " extensity" or " voluminousness," and appear to

be data of sight 2 as well as of touch. Superficial extension (or

coloured surface) certainly appears to be a direct datum of sight. 6

The three dimensions of extension (length, breadth, and depth)

not separately and in the abstract, but together, as "concrete

voluminousness" are a direct datum of touch (i.e. of the passive

sense of pressure, and the active or muscular sense of motion

and resistance, combined) ; but whether the third dimension of

space is a direct datum of sight, i.e. whether, independently of

tactual, muscular, and motor sensations, the sense of binocular

vision can or does reveal to us depth or distance from the per-

ceiver, or objects in relief, is a question to which psychologists

usually reply in the negative. 4 But, even so, the appellation,

"common sensibles," is a justifiable description of the concrete

modes of extensity which have been so designated.

 I. All men have

an invincible persuasion that certain objects appear to them, and

are perceived by them, as distinct from, and outside of, them

selves, and as endowed with certain features such as extension,

impenetrability, shape, colour, etc. This feeling of externality^-

of such objects has never been denied by even the most extreme

sceptics.

II. Hence, men spontaneously judge that outside themselves,

and independently of their conscious perceptions, there actually

exist real things endowed with such features and qualities. This

we may call the spontaneous judgment of externality or otherness.

It involves two sorts of judgment, the judgment of existence,

that a "reality or realities external to the perceiver exist," and

the judgment of nature, that " this reality is such and such,"

e.g. soft, spherical, cold, yellow, sweet, etc. ; that " this is an

orange," "that, is an oak," "that is a horse," etc., etc. That

men spontaneously make and believe such judgments is likewise

universally admitted.

III. Antecedently to philosophical reflection men spontane

ously believe that the existence of a real, external, material

universe, existing independently of their perception of it, is as

indubitably evident to them as their own individual existence.

Nay, when we want to express the strongest intellectual certi-

1 Some authors say that on reflection this feeling of externality can be indubit

ably detected only in the data of sight ; others only in the data of touch ; others only

in these two domains of data ; others in the data of hearing as well ; others even in

the data of taste and smell. Cf. JEANNIERE, op. cit., p. 385 n. All sensations

reveal objectivity of course ( 19). But not all reveal externality, e.g. the organic

sensations whereby we become aware of the internal states and conditions of our

bodies. Similarly, the feeling of volnmitiousness or extensity, which is held by some

psychologists to characterize the data of touch alone, is held by most to affect the

data of sight as well, and by many to affect in some measure the data of all the

senses. Cf. JEANNIERE, op. cit., p. 401, n. 2.

37

38 THEOR Y OF KNO WLEDGE

tude of the truth of any judgment we describe it in terms

borrowed from sense perception, we say that such a truth is

manifest^ as clear as noonday, palpable, that we see it, etc., etc.

It is admitted that so irresistibly does this persuasion of the

independent existence of an external universe force itself upon

men that even those cannot eradicate it, but continue to act on

it, who come to regard it as theoretically indefensible (37).

IV. We classify the conscious data or objects of sense per

ception into certain broad, clearly distinct and mutually irre

ducible domains : into colours, sounds, tastes, smells, organic

states (of bodily pleasure, pain, etc.), pressure, resistance to

muscular effort, heat and cold, size and shape, rest and motion,

position, location, number, etc. It is admitted by all that we

have such diversely qualified data or objects of sense awareness.

V. Even a moderate measure of reflection on the various

qualities which we thus apprehend in the " external " data of

sense awareness, and which we ascribe to things spontaneously

judged to exist outside us and independently of our perception,

will convince us that some of those qualities seem to be more

dependent than others, for what they appear to be, on the actual

condition of the bodily sense organs, 1 to be more relative than

others to the self as sentient subject. When, for instance, we

say that this stone is hard, this orange is round, this grass is

green, these clouds are moving ; and then that this water is

warm, this wine is mellow, this perfume is pleasing, we realize

that the former group of qualities belong to the subjects to which

we attribute them, more absolutely and independently of our

selves, than the latter group do to theirs : that what feels warm

to one hand may feel cold to the other, that the same "thing"

may not "taste " or " smell " the same to different people, or to

ourselves at different times, etc. This broad fact is undisputed ;

not so, however, its significance, or its application in detail.

VI. Reflection also reveals, among the qualities of sense data

or objects, another broad distinction which has been recognized

in one form or other at all times by students of sense perception :

1 Or, of the self as a corporeal, organic, conscious subject. The body, with its

sense organs, is apprehended by us in two distinct ways : (a) by our external senses

in the same way as we apprehend the " external " universe, and as similar to the

latter (corporeal, or material, extended, etc.) ; (b) by the internal, muscular, organic

senses, the functioning of which accompanies that of the external senses and con-

comitantly reveals the bodily organism as the sentient-conscious self or subject.

The former apprehension may be described as objective, the latter as subjective.

VALIDITY OF SENSE PERCEPTION 39

the distinction between what scholastics have called the " proper

sensibles " (sensibilia proprid} and the "common sensibles"

(sensibilia communia). The former are the concrete qualities, or

"qualified" data or objects, of each separate sense: colours,

sounds, tastes, odours, pressures or resistances, temperatures,

organic states. The latter are concrete, "qualified" data or ob

jects, apprehended in common or by more than one sense channel :

shape (forma vel figura), size or volume (inagnitudd], number

(inultitudd}?- rest, motion. The former are also called the

"secondary" sense qualities, and the latter the "primary" sense

qualities, of matter (or of "corporeal " or "sense" data).

This division of sense data into "primary" or "common,"

and "secondary" or "proper," is recognized as grounded in

consciously apprehended differences between the two sets of data

respectively. But its significance and implications are much dis

puted. The former or " common " sensibles are clearly all con

crete modes of " extensity" or " voluminousness," and appear to

be data of sight 2 as well as of touch. Superficial extension (or

coloured surface) certainly appears to be a direct datum of sight. 6

The three dimensions of extension (length, breadth, and depth)

not separately and in the abstract, but together, as "concrete

voluminousness" are a direct datum of touch (i.e. of the passive

sense of pressure, and the active or muscular sense of motion

and resistance, combined) ; but whether the third dimension of

space is a direct datum of sight, i.e. whether, independently of

tactual, muscular, and motor sensations, the sense of binocular

vision can or does reveal to us depth or distance from the per-

ceiver, or objects in relief, is a question to which psychologists

usually reply in the negative. 4 But, even so, the appellation,

"common sensibles," is a justifiable description of the concrete

modes of extensity which have been so designated.