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Newton; il a fait peut-être plus que Newton.' From this it might be supposed higher merit to see that there is a problem to be solved than to solve it!
But we must now proceed, as we proposed, to offer a few remarks on some of the principal points of the Cartesian philosophy. And first of 'innate ideas.'
One of the most voluminous, yet least satisfactory controversies ever carried on among men, is that respecting the origin of human knowledge and the genesis of our ideas. It is whimsical, at first sight, that men should be more agreed about the deductions and results derived from their first principles than about the origin of the first principles themselves; that the house should be apparently strongerthough not really stronger-than the foundations. But it is for the usual reason; the foundations are out of sight. Men certainly believe that two and two make four; and that two straight lines will not inclose a space; but whether these things be 'generalisations from experience,' or assume the shape of axioms (as soon as the very terms are propounded and understood) in virtue of the very constitution of the mind itself, we see by the differences of opinion between even such men as Dr. Whewell and Mr. John Mill, that men are not agreed. That there is a material world, they are pretty unanimous; but why they think so, the most acute of them are still puzzled to say; they are also tolerably agreed that there is a God, but whence that idea is collected, or at all events whence it may be most unexceptionably and summarily inferred; whether it does not anticipate all demonstration; and if not, how it may be best demonstrated, as to all this, metaphysicians are perpetually wrangling. In brief, in relation to much of
philosophy, mankind seem exactly in the contrary position to that in which Epictetus represents them. The most important roos in philosophy,' says he, is that which respects the application of theorems, as for example, that we must not lie; the second, the demonstration of this; as for example, why we ought not to lie; and the third, the force of the demonstration itself;' or the wherefore of the why, as we may express it. 'But now,' continues he, 'wholly forsaking the first, we addict ourselves almost exclusively to the last; thus we lie fast enough; but how it may be demonstrated that we ought not to lie, we have at our fingers' ends.' It is just the contrary, with the greater part of the primary truths which we have above enumerated; they are embraced, but the grounds of them are disputed. It is quite true that philosophers are as willing as ever to busy themselves supremely about the why, and the why of the wherefore; but, it appears, without the same success; for whereas we all believe and act on the belief that two and two make four, that there is a material world, and so forth, philosophers have not the why and the wherefore quite so much at their command.
Steady indeed must be the hand, bright the lamp, and keen the eye, which ventures to explore those depths of our nature in which our ideas originate. The stream of knowledge, however bright it sparkles at last in the sun, has its font in a dark mountain cave, and issues to the day through many a secret winding channel. Long before men are in a condition to investigate this obscure subject, to analyse the sources of their knowledge, the process (the result of many conditions) has been completed, and the products have become hopelessly complicated. The mind constituted so and so, having its own laws and con
ditions of thought independently of experience, but also subjected to inevitable conditions of development from that experience, without which it would never develope at all, has been so perpetually and so equally under the influence of both sets of conditions, and that at periods long anterior to the dawn of reflection, that it is now no longer possible to ascertain with exact precision what is due to one and what to the other. If we could separate the two classes of influence, or rather if we could calculate not only their combined action, but their perpetual interaction; if, as mathematicians say, we could have one element vary and the other remain constant, and then the second vary, and the first remain constant, we should be able to see what is the effect of each in the total result. But this is impossible, and hence the difficulty. As Descartes has observed in the first sentence of his 'Principia,' in language which reminds one strongly of many passages in the Novum Organum,'-'Since we were all once children, and in that condition formed various judgments concerning external objects, before we had arrived at the entire use of our reason, we are misled, by many prejudices, from the knowledge of the truth; from which prejudices it does not seem possible that we should be liberated, except by endeavouring to doubt, once for all in our lives, of all those things in which we may discover only the smallest suspicion of uncertainty.' The evil is more apparent than the remedy.
That there are the two above-mentioned distinct sets of conditions essential to the genesis and formation of our ideas, is now admitted with tolerable unanimity by philosophers; they, for the most part, alike maintain that the mind is originally constituted with its own fundamental laws of thought, which will
inevitably cause it to develope only to certain effects --that is, by which it will develope thus and thus, and no otherwise, and that at the same time a certain external influence, a contact with the outward world, is absolutely necessary,—without which it would never develope at all. On the one hand, as Professor De Morgan well puts it, 'Either we have ideas which we do not acquire from or by means of communication with the external world (experience, trial of our senses), or there is a power in the mind of acquiring a certainty and a generality which experience alone could not properly give;' and on the other hand, without that experience, the mind, for aught we know, would remain in perpetual slumber; this experience being, as far as either facts or consciousness can teach us, an invariable condition of the very first germination of thought. The external world presents us with abundant illustrations of an analogous union of similarly diverse conditions of development. Thus the internal structure of the flower is such that it will develope only to a certain colour, form, fragrance, and no other; yet without the sun, the wind, the dew, the rain, the soil, it will remain in the germ. In like manner, the eye, were it otherwise constructed than it is, would not see, whatever the abundance of light; and were it constructed as it is, could see just as little if there were no light at all.
But in that complex result which flows from this perpetual, reciprocal, and inveterately entangled interaction of the diverse components of thought, it is almost hopeless to estimate the precise portion of effect due to either alone. The result itself becomes an insoluble compound. As in a product of chemical affinities, the separate elements have disappeared; the acid and alkali have alike vanished; the silica and the
potash are no longer visible in the transparent crystal. And of the hopelessness which must probably attend every attempt at complete analysis, we may see proof in the fact that two such philosophers, even in our own day, as Dr. Whewell, and Mr. J. S. Mill, can yet come to such opposite conclusions as to the elements contributed severally by the internal constitution of the mind and its external experience, in the formation of our ideas of that class of truths which have been deemed (inasmuch as their contraries appear impossible) necessary. Dr. Whewell contends that even such a principle as the equal pressure of fluids in all directions which, at first sight, seems so little selfevident, that the curious fact which it alone explains is still called the Hydrostatic Paradox-was not derived from experience in any exact sense of that phrase,'* but that the mind can pronounce on its à priori certainty. Similarly he contends that the first law of motion, which was at first regarded as an enormous paradox-and even the law of definite proportions in chemistry (a fact fully established only in our own age), though historically collected from experience, yet have an evidence far beyond it;-the mind, in virtue of its own laws of thought, being competent to pronounce not only that these facts are but must have been; that it attains a point of view from which it can pronounce that the first might certainly have been discovered independently of experience,' † and that the contrary of the second is 'inconceivable.' Mr. Mill, on the other hand, contends, and with great force and ingenuity of argument, that even axioms are 'experimental truths,' 'generalisations from experience;' that however the mind may and does transmute into general truth the facts
* Phil. Ind. Sciences, vol. i. p. 203. † Ibid. p. 213.