Зображення сторінки
PDF
ePub

sion being the continuation of the nervous circuit, its reproduction must be of the same nature. The idea of an impression is then a reproduction in a feebler form of those nervous conditions which cause the impression itself. This explains why the idea of a movement, when it becomes very lively, induces a movement spontaneously of itself, without the intervention of our will, the excited nervous current being as intense as in the case of a real impression coming from without.1

“The tendency of the idea of an action to produce the fact, shows that the idea is already the fact in a weaker form. Thinking is restrained speaking or acting. ... The tendency of an idea of the mind to become the reality is one of the controlling forces of our constitution, it is a distinct source of active impulses. Our chief active faculty is expressed by the will, or volition, whose nature it is to urge us from pain on to pleasure. But the disposition to pass from a mere recollection, imagination, or idea to the action that it represents—not merely to think an act, but to do it—is also a determining principle of human conduct.' 2

The author shows how many curious facts in psychology are explained by this tendency of the idea to realize itself; the fascination exerted by a precipice, the phenomena produced by fixed ideas, by magnetic sleep, and the sensation caused by sympathy.

Let us now examine a case of association by contiguity, between the data of the various senses : a subject already handled by the author, and again resumed. These repetitions, hardly justifiable in a literary work, appear to me to be useful in this case; they permit us to see the different aspects of the question more clearly. We already know that knowledge of the exterior world is due to the associated sensations of touch, sight, and the muscular sense.

“The relations between these four distinct facts-namely, ocular adjustment for seeing an object, the extent of the image on the retina, the distance, and the true magnitude of the object,

1 On this mechanism of the idea returning to its starting-point, see Lélut, l'Amulette de Pascal, Introduction. See also Chevreul, Du Pendule explorateur.

Bain, The Senses and the Intellect, p. 346.

2

are what we have to consider, for we find that in the educated eye these circumstances are suggestive of one another.' “Thus as we approach the object, or as it is brought nearer to us, the magnitude of the picture on the retina increases; the inclination of the optic axes required to cause the pictures to fall on corresponding places of the retina becomes greater." .. Accordingly, Mr. Wheatstone has devised an instrument, being a modification of his reflecting stereoscope, whereby he can expose pictures to the two eyes in such a manner that the distance can be changed while the convergence of the two eyes remains the same, or the convergence be altered while the distance remains the same ; thus disassociating two facts that constantly go together in ordinary vision. The result of the experiments showed the influence of both circumstances, namely, the convergence of the eyes and the size of the picture on the retina (which is greater as the object is nearer) in determining our judgment of distances. He finds that the distance of the object remaining the same, the greater convergence of the two eyes makes the object seem smaller, this increased convergence being required in ordinary vision when a thing is brought nearer. It appears, therefore, that while the retinal magnitude is unaltered, greater convergence gives a perception of smaller size. On the other hand, leaving the inclination of the axes unchanged, and bringing the pictures nearer, thereby increasing the picture on the retina, there is a perception of increased size in the object. ... Now, according to Mr. Wheatstone, the inclination of the axes, in company with a given retinal picture, suggests the magnitude first, and from the true magnitude thus known and the retinal magnitude we infer the distance.'

Perhaps some intractable adversary of metaphysics will reproach Mr. Bain with having gone away from experimental analysis to ask how we perceive the exterior world ? and why we believe in it? We shall reply that he submits a few remarks.

* There is no possible knowledge of the world, except in reference to our minds. Knowledge means a state of mind ; the

[ocr errors]

1 Wheatstone.

2 Bain, Senses and Intellect, p. 377, 378.

notion of material things is a mental thing. We are incapable of discussing the existence of an independent material world ; the very act is a contradiction. We can speak only of a world presented to our own minds. By an illusion of language, we fancy that we are capable of contemplating a world which does not enter into our own mental existence; but the attempt belies itself, for this contemplation is an effort of mind.' 1

Let us observe, besides, that which we ourselves put into the act of perception. Solidity, extension, and space, which are the fundamental properties of the material world, respond to certain movements of our own bodies, and exist in our minds in the form of sentiments of force, and of visual and tactile impressions. The sense of exteriority is then the consciousness of particular energies and activities proper to us. All the difference between ideal sensation and an actual sensation is, that the latter is entirely at the mercy of our movements. We turn our head to the right, or to the left; we move our body, and our perception varies; thus we arrive at distinguishing things, which our movements cause to change their places, from the ideas or dreams which vary of themselves, when we are in repose. In communicating with other beings, and in knowing that they have the same experiences as ourselves, we form an abstraction of our past experiences, and of those of others, and that is the greatest height we can attain with relation to the material world.

Nevertheless, a possible world implies a possible mind to perceive it, just as an actual world implies an actual mind.'

The conclusion at which Mr. Bain arrives in these remarks, so far as we can define it, would not displease an idealist, since it would place a portion of the reality of the world in the mind : the feeling and the felt being for him not two terms, but two complementary parts of the same whole.

He says in a note to his recent edition of James Mill :

“The contrasted terms “Object” and “Subject are the least exceptionable for expressing the fundamental antithesis of consciousness and of existence. Matter and Mind, External and Internal, are the popular synonyms, but are less free from mis

[ocr errors]
[blocks in formation]

leading suggestions. Extension is the object fact by pre-eminence ; Pleasure and Pain are the most marked phases of pure subjectivity. Between the consciousness of extension and the consciousness of a pleasure there is the broadest line that can be drawn within the human experience; the broadest distinction in the whole universe of being. These then are the Object and Subject extremes, and, in the final analysis, the Object extreme appears to be grounded on the feeling of expended muscular energy.' 1

IV.

cesses.

A second method of association is founded upon resemblance. The law which regulates it is thus enunciated : “Actions, sensations, thoughts, or emotions which are present, tend to revive those which resemble them among anterior impressions or states.'

Association by contiguity serves above all to acquire, association by resemblance serves above all to discover : it plays a preponderant part in reason, and in the various scientific pro

At one time we grasp the resemblances between continued co-existent aggregates ; for example, we forget the differences which separate a horse, a fall of water, a steamengine, in order to see in them nothing but a motive power. At another time we grasp resemblances in successions. Thus, in studies of embryology, the same being is recognised through all the different phases of its evolution. In the comparative study of social and political constitutions, understood in the manner of Aristotle, Vico, Montesquieu, Condorcet, Hume, De Tocqueville, we must have a penetrating mind; in other words, a strong identifying faculty, which can unite and extract obscure resemblances from differences.' 2

The progress of a classification consists of associating in the same groups beings more and more similar ; in passing from superficial identities to fundamental identities, from the Aristotelian division of animals into terrestrial, marine, and aërial, to Cuvier's division, founded upon true nature, and not upon accidental resemblances.

1 Mill's Analysis, note I, p. 5, line 20.

2 Vol. i. p. 519.

In the mineral kingdom we naturally group the metals together. A greater progress consists in discerning, as Davy has done, that there is a metallic substance in soda and potash, by building upon purely intellectual resemblances.

In the vegetable kingdom, division into trees and shrubs preceded that of Linnæus. At a later date Goethe grasped an analogy between the flower and the entire plant. Oken recognised the plant in the leaf.

In the animal kingdom comparison between the different part which compose each individual leads to the discovery of Homologies. Oken, walking one day in a forest, came upon the bare and whitened skull of a wild beast.

He took it up, examined it, and discovered that the skull consists of four vertebræ, that it is only a continuation of the vertebral column.

The modes of reasoning and scientific processes founded upon an association by resemblance are arranged by Mr. Bain under these four titles :

Ist, Classification, abstraction, generalization of notions, general names, definitions; the classification consisting in grouping objects according to resemblance, whence results a generalization, or abstract idea which represents what there is in common in the group; and a definition which expresses the common characteristics of the class.

2d, Induction, indirect generalization, conjoint properties, affirmations, propositions, judgments, laws of nature.

Here we obtain no longer ideas, as in the first case, but judgments.

3d, Inference, deduction, reasoning, syllogism, extension of inductions. Mr. Bain adopts, without restriction, the doctrine of Stuart Mill, that all reasoning goes from the particular to the particular. The syllogism is only a precaution against error, or, as Mr. Herbert Spencer says, a verification.

4th, Analogy. Here is less than identity; hence those false comparisons which have given rise to false conclusions, such as the assimilation of society to the family, which would tend to make of a sovereign a guardian or a despot.

« НазадПродовжити »