Chapter III: Conception (2)

_Inconsistent and contradictory Testimony of Sense._--But it may be replied that the testimony of sense is often inconsistent with itself, and contradictory of itself. What is sweet to one is sour and bitter to another. What seems a round tower in the distance becomes a square one as you approach; and the straight stick that you hold in your hand appears crooked when thrust into the water. There is in reality, however, no contradiction or inconsistency in the cases supposed. The change of circumstances accounts in every instance for the change of appearance. In the case of the stick, for example, the different density of the water accounts for the refraction of the rays of light that pass through it, and this accounts for the crooked appearance of the stick that is only partially submerged. So in the other cases; it is no contradiction that an object which appears round at a distance of ten miles, should appear square at the distance of so many rods--or that the taste of two persons should not agree as to the savor of a given object.

_Deceptions of Sense._--It may be further objected that in certain states of the physical organism, sensations are experienced which seem to be of external origin, but are really produced by internal changes; and that in such cases we have the same perceptions, see the same objects, hear the same things, that we should if there were a corresponding external reality, while nevertheless there is no such reality, and it can be proved that there is none. If this may happen in some cases, why not in others, or in all?

_Reply._--I reply, the simple fact, that in the case supposed the deception can be detected and proved, shows the difference between that and ordinary perception. If the senses were not habitually reliable, we could not detect the mistake in this particular instance. If all coin were counterfeit, how could we detect a counterfeit coin? We know, moreover, how to account for the mistake in the case before us. It occurs, by the supposition, only in a certain state of the organism, that is, only in a diseased, abnormal condition of the system. The exception proves the rule.

_Distinction of direct and indirect Testimony._--A distinction is to be made, in the discussion of this subject, between the direct and indirect testimony of the senses, between that which is strictly and properly perception, and that which is only conception, judgment, inference. What I really perceive, for example, in the case of the distant tower, or the stick partially under water, is only a given appearance; I _infer_ from that appearance that the tower is round and the stick crooked, and in that inference I am mistaken. My judgment is at fault here, and not my senses. They testified truly and correctly. They gave the real appearance, and this was all they could give, all they ever give. This has been well stated by Dr. Reid, and, long before him, the same ground was taken, in reply to the same objection, by Aristotle and also by Epicurus.

_Direct Perception gives what._--In regard to direct and immediate perception, the case is different. Here the testimony is positive to the existence of the object. When something resists my voluntary movement, I am conscious of that resistance, conscious of something external and resisting. I cannot deny the fact of that consciousness. I may, however, deny the correctness, the truthfulness of what consciousness affirms. To do this, however, is to put an end to all reasoning on the subject, for, when we give up consciousness as no longer reliable, there is nothing left to fall back upon. If any one chooses to leap from this precipice, we can only say _finis_.

§ VII.--HISTORICAL SKETCH.

I. OF DIFFERENT DIVISIONS OF THE QUALITIES OF BODIES.

_The Greek Philosophers._--The distinction of the qualities of bodies into two classes, differing in important respects, is by no means a modern one. It was recognized by some of the earlier Greek philosophers, who held that the sweet, bitter, hot, cold, etc., are rather affections of our own senses than proper qualities of matter, having independent existence. Subsequently the view was adopted by Protagoras, and by the Cyrenean and Epicurean schools. Plato held it, and especially and very fully, Aristotle, who calls the qualities to which we have referred, and which are usually denominated secondary, _affective_ qualities, because they have the power of affecting the senses, while the qualities now usually termed primary, as extension, figure, motion, number, etc., he regards as not properly objects of sense. The former class he calls proper sensibles, the latter, common.

_The Schoolmen._--The _schoolmen_ made much of this distinction, and held, with Aristotle, that the qualities now called primary, require, for their cognition, other faculties than those of sense.

_Doctrine of Galileo._--_Galileo_ points out the true ground and philosophy of this distinction, and also gives the name _primary_ to the class referred to, viz., _those qualities which are necessary to our conception of body_, as for example, figure, size, place, etc., while, on the contrary, colors, tastes, etc., are not inherent in bodies, but only in us, and we can conceive of body without them. The former are real qualities of bodies, while the latter are only conceptions which give us no real knowledge of any thing external, but only of the affections of our own minds.

_The Moderns._--_Descartes_ and _Locke_ merely adopted these distinctions as they found them, without essential modification. So also did _Reid_ and _Stewart_, although both included among the primary qualities some which are properly secondary, as roughness, smoothness, hardness, softness. Indeed Stewart restricted the primary qualities to those and such as those just named.

_Hamilton._--No writer has so fully elaborated this matter as Sir William Hamilton, to whom we are indebted mainly for the historical facts now stated, and whose dissertations are and must ever remain an invaluable thesaurus on the philosophy of perception. So complete and elaborate is his classification of the qualities of matter, that I shall be pardoned for giving a synopsis of its principal points in this connection.

_Hamilton's Scheme--General Divisions._--He divides the qualities of bodies into three classes, which he calls primary, secundo-primary, and secondary. The primary are thought as essential to the very notion of matter, and may be deduced _à priori_, the bare notion of matter being given; while the secundo-primary and the secondary, being accidental and contingent, must be deduced _à posteriori_, learned by experience. His deduction of the primary qualities is as follows:

_Primary Qualities._--We can conceive of body only as, I. Occupying space; II. Contained in space. Space is a necessary form of thought, but we are not obliged to conceive of space as occupied, that is, to conceive of matter. When conceived it must be under the conditions now named.

I. The property of occupying space is _Simple Solidity_, which implies, _a._ Trinal extension, or length, breadth, and thickness; _b._ Impenetrability, or the property of not being reduced to non-extension. Trinal extension involves, 1. Number, or Divisibility; 2. Size, including Density; 3. Shape.

II. The attribute of being contained in space, affords the notion, 1. Of Mobility; 2. Of Position.

The essential and necessary constituents then of our notion of matter are, 1. Extension (comprising under it, 2. Divisibility; 3. Size; 4. Density; 5. Figure); 6. Ultimate Incompressibility; 7. Mobility; 8. Situation. These are the primary qualities, products, in a sort, of the understanding, developing themselves with rigid necessity out of the given notion of substance occupying space.

_Secundo-Primary Qualities._--The secundo-primary are contingent modifications of the primary, all have relation to space, and motion in space, _all are contained under the category of resistance_, or _pressure_, all are learned or included as results of experience, all have both an objective and subjective phase, being at once qualities of matter, and also affections of our senses.

Considered as to the _sources_ of resistance, there is, I. That of _Co-attraction_, under the forms of _a_, Gravity, _b_, Cohesion; II. That of Repulsion; III. Inertia; all which are capable of minute subdivision. Thus from cohesion follow the hard and soft, firm and fluid, tough and brittle, rigid and flexible, rough and smooth, etc., etc. From repulsion are derived compressible and incompressible, resilient and irresilient.

_Secondary Qualities._--The secondary qualities are, as apprehended by us, not properly attributes of body at all, but only affections of our nervous organism. They belong to bodies only so far as these are furnished with the power of exciting our nervous organism to the specific action thus designated. To this class belong color, sound, flavor, savor, tactile sensation, feeling of heat, electricity, etc. Such also are titillation, sneezing, shuddering, and the various sensations, pleasurable or painful, resulting from the action of external stimuli.

_These Classes further distinguished._--Of the qualities thus derived, the primary are known immediately in themselves, the secondary only mediately in their effects on us, the secundo-primary both immediately in themselves, and mediately in their effects on us. The primary are qualities of body in relation to body simply, and to our organism as such; the secundo-primary are qualities of body in relation to our organism, not as body in general, but as body of a particular sort, viz.: propelling, resisting, cohesive; the secondary are qualities of body in relation to our organism as excitable and sentient. The primary may be roundly characterized as mathematical, the secundo-primary as mechanical, the secondary as physiological.

_Reasons for retaining the twofold Division._--Such, in brief outline, are the principal points of Hamilton's classification. While following in the main the distinctions here indicated, I have preferred to retain the old division into primary and secondary, as at once more simple, and sufficiently accurate, merely dividing the secondary into two classes, the mechanical (secundo-primary of Hamilton), and physiological. We are thus enabled, not merely to retain a division and nomenclature which have antiquity and authority in their favor, and are well-nigh universally received, but we avoid the almost barbarous terminology of Sir William's classification--while, at the same time, we indicate with sufficient precision the important distinction between the so-called secundo-primary and secondary qualities.

II. OF DIFFERENT THEORIES OF PERCEPTION.

_Realists and Idealists._--There are two leading theories, quite distinct from each other, which have widely prevailed, and divided the thinking world, as to the philosophy of perception. The one maintains that in perception we have _direct cognizance_ of a real external world. This is the view taken in the preceding pages, and now generally held by psychologists in this country, and to some extent in Europe But for a long period, the prevalent, and in fact, until the time of Reid in Scotland, and Kant in Germany, the almost universally-received opinion was the reverse of this--that in perception, as in any and all other mental acts, the mind is conscious only of its own ideas, cognizant of itself and its own states only, incapable, in fact, of knowing any thing external to itself. Those who hold the former view are termed _Realists_, the latter _Idealists_.

_Further division of the latter._--The latter, however, are of two classes. The _Absolute Idealists_ hold that the notion we have of external things is purely subjective, having no external counterpart, no corresponding outward reality. In distinction from this the greater part maintain that while we are cognizant, directly and strictly, of nothing beyond our own minds, nevertheless there is an external reality corresponding to the idea in our minds, and which that idea represents. Hence they have been designated _Representative Idealists_, or, as Sir William Hamilton terms them, Cosmothetic Idealists.

_Further Distinction._--Of these latter, again, some hold the idea which we have of an external world to be merely a state or modification of the mind itself; others regard it as a sort of intermediate connecting link between mind and matter. The former may be called egoistic, and the latter non-egoistic.

_Summary of Classes._--We have then these three great classes--the _Natural Realists_, the _Absolute Idealists_, and the _Representative Idealists_ comprising the Egoistic and Non-Egoistic divisions.

_Distinguished Writers of the different Classes._--On the roll of absolute idealism are names of no small distinction: Berkley and Hume, in England, Fichte and Hegel, in Germany, are of the number; while among the representative idealists one finds Descartes, Arnauld, Malebranche, Leibnitz, Locke, in fine, the greater number of philosophic writers from Descartes onward to the time of Reid. Subsequently even, we find a writer of no less repute than Dr. Brown assuming, as the basis of his philosophy of perception, the exploded theory of representative idealism, under the egoistic form. Of natural realists since the time of Reid, Sir W. Hamilton is the most distinguished.

_Origin of Representative Idealism._--The doctrine of representative perception doubtless originated in the difficulty of conceiving how a purely spiritual existence, the human mind, can, by any possibility, take cognizance of, or be affected by, a purely material substance, the external world. The soul seated in its presence-chamber, the brain, can cognize nothing beyond and without, for nothing can get except where it is present. It must be, then, said the philosophers, that in order to the mind's perceiving any thing of that which lies beyond and without its own immediate locality, there must come to the mind from that outer world certain little images bearing some resemblance to the things without, and _representing_ to the soul that external world. These images--more refined than matter, less spiritual than mind itself, of an intermediate nature between the two--they termed ideas.

_Tendency of Representative to Absolute Idealism._--It is easy to see how such a doctrine would lead almost inevitably to _absolute idealism_. If we do not in perception take cognizance directly of matter external, but only of certain images or ideas in our own minds, then how do we know that these images _correctly represent_ the external reality, which we have never cognized, and never shall? How do we know, in fact, that there _is_ any such external reality? What evidence have we, in a word, of the existence of any thing beyond and without our own minds? This was the actual result to which Berkley and Hume drove the then prevalent philosophy of Europe, as to a legitimate and inevitable result.

_Relation of Dr. Reid to this Controversy._--To Dr. Reid belongs the credit of rescuing philosophy from this dangerous extreme, by showing the utter falsity of the ideal theory. He took the ground that the existence of any such representative images in the mind is wholly without proof, nay more, is inconceivable; that while we can conceive of an image of form or figure, we cannot conceive of an image of sound, or of taste or smell. The hypothesis is wholly without foundation. But even if it were conceivable and established by sufficient evidence, still it would explain nothing as to the manner in which the mind perceives external objects. It relieves no difficulty. If the representative image be itself material, how can the mind take cognizance of it? If not material, how can it represent matter, and how can the mind know that it does represent correctly the external object?

_State of the Matter since Reid._--Since the time of Dr. Reid, this theory of representative perception, at least in this non-egoistic form, has been for the most part abandoned, and philosophers have been content to take the ground indicated by consciousness, and the common sense of mankind, that in perception we take direct cognizance of the external object.

_Position of Hamilton._--It remained for Sir W. Hamilton to complete the work which Dr. Reid began, by showing that the representative theory, in its finer or egoistic form, as held by Dr. Brown and others, is equally untenable or unsound; that it makes little difference whether we regard the image or idea, which we take to represent the external object, as something distinct from the mind itself, or whether we view it as a mere modification or state of the mind, so long as we make any thing of the sort the direct object of perception instead of the real external thing. Idealism is the result in either case, and philosophical skepticism the goal. In place of any and all such views, Hamilton maintains, with great power and earnestness, the doctrine of natural realism--that in perception we are cognizant immediately and directly of the external object.

As no other writer has so fully elaborated this department of science, it may be of service to present in this connection the chief points of his theory.

_Chief Points of Hamilton's Theory of Perception._--All perception is immediate cognition; we perceive only what we apprehend as now and here existent; and hence what we perceive is either in our own organism, viewed as material, extended, etc., or else is in immediate correlation to it. The organism is, in perception, viewed as not-me; in sensation, as of the me.

_What is given in Perception proper._--What we apprehend in perception proper is: 1. The primary qualities of body as pertaining to our own organism; 2. The secundo-primary qualities of bodies in correlation to it. (See Hamilton's division of qualities of bodies, as above.)

_Primary Qualities of external Objects, how known._--The primary qualities of things external to our organism we do not perceive immediately, but only infer, from the effects produced on us by them. Neither in perception nor sensation do we apprehend immediately, or in itself, the external cause of our affection or sensation. That is always unknown to consciousness, known only by inference or conjecture.

_External Existence, how learned._--The existence of the world without is apprehended not in a perception of the primary qualities of things external, but of the secundo-primary--_i. e._, in the consciousness that our movements are resisted by something external to our organism. This involves the consciousness of something external, resisting. The two things are conjunctly apprehended.

_This presupposes what._--This experience presupposes the notion of space, and motion in space. These are inherent, instinctive native elements of thought, and it is idle to inquire how we come by them. Every perception of sensations _out of_, and distinct from, other sensations gives occasion for conceiving the idea of space. _Outness_ involves it.

_Points of Difference between this Theory and Reid's._--The system, as thus stated, differs in some respects materially from the doctrine of perception advanced by Dr. Reid, and generally adopted since his time by the English and Scotch philosophers. According to Hamilton, perception is not, as held by Reid and others, the _conception_ of an object _suggested_ by sensation, but the direct cognition of something. We do not merely _conceive_ of the object as existing, and _believe_ it to exist, we _know_ it and _perceive_ it to exist. Nor does sensation precede, and perception follow, as generally stated, but the two are, in time, conjunct, coëxistent. Nor do we perceive the secondary qualities of bodies, as such, but only _infer_ them from our sensations. Neither do we perceive distant objects through a medium, as usually held, but what we perceive is either the organism itself, as affected thus and thus, or what is directly in contact with it, as affecting and resisting it. Extension and externality, again, are not first learned by _touch_, as Reid holds, and most subsequent writers, both English and American, but in other ways; the former, by the perception of the primary qualities of our own organism, as the seat of sensations distinct from other sensations elsewhere localized; the latter, by the resistance which we experience to our own locomotive force. Finally, sensation proper is not, as with Reid and others, an affection purely of the mind, but of mind and body as complex. Its subject is as much one as the other.

INTELLECTUAL FACULTIES.

PART SECOND

THE

REPRESENTATIVE POWER

GENERAL OBSERVATIONS.

_Nature of this Power--Its various Forms._--It is in the mind's power to conceive or represent to itself an object not at the time present to the senses. This may take place in several forms. There may be the simple reproduction in thought of the absent object of sense. There may be, along with the reproduction or recurrence of the object, the _recognition_ of it as a former object of sensation or perception. There may be the reproduction of the object not as it is, or was, when formerly perceived, but with variations, the different elements arranged and combined not according to the actual and original, but according to the mind's own ideals, and at its will. This latter form of conception is what is usually termed imagination--while the general term memory, as ordinarily employed, is made to include the two former. While using the term in this general sense, we may properly distinguish, however, between mental reproduction, and mental recognition, the latter being strictly the office of memory.

All these are but so many forms of the representative power. We may designate them respectively as the _reproductive_, _recognitive_, and _creative_ faculties. The mind's activity is essentially the same under each of these forms. The object is not _given_ but _thought_, not presented to sense, but _represented_ to the mind. The process is reflective rather than intuitive. It is a matter of _understanding_ rather than of _sense_ or of _reason_. It is a conception, not a perception or an intuition, and it is a simple conception of the object as it is or is conceived to be, in itself considered, and not in relation to other objects.