"Que dirons-nous, maintenant," writes Hobbes, "si peut-être le raisonnement n'est rien autre chose qu'un assemblage et un enchainement de noms par ce mot est? D'où il s'ensuivroit que par la raison nous ne concluons rien de tout touchant la nature des choses, mais seulement touchant leurs appellations, c'est-à-dire que par elle nous voyons simplement si nous assemblons bien ou mal les noms des choses, selon les conventions que nous avons faites à notre fantaisie touchant leurs significations."

To this curious passage Descartes very aptly replied:

"L'assemblage qui se fait dans le raisonnement n'est pas celui des noms, mais bien celui des choses signifiées par les noms ; et je m'étonne que le contraire puisse venir en l'esprit de personne."

In reasoning on some subjects, little progress, indeed, could be made without language. It is not always seen, however, that this observation is applicable far more to written than to spoken language, to visible symbols than to articulate sounds. Yet no one would dream of attempting on this account to restrict logic to written language.

The great expedients which have been devised to assist the intellect in the most abstract calculations,

* Quoted from the works of Descartes by Mr. Hallam in his Introduction to the Literature of Europe, vol. iii. p. 248.

owe their efficiency to their symbols being presentable to the eye at pleasure, and thus constituting visible fixed stations, where the mind can repose, where it can always find what has been already accomplished, and from which it can again start in pursuit of new results. Sounds, it is true, are associated with these visible symbols; but they play a subordinate part in such processes, and would be incapable alone of enabling the mind to proceed beyond a comparatively short distance.

Reasoning, in brief, is one species of thinking; and, like all other thinking, except that of which language is itself the subject, may be carried on independently of words. When language is used, it forms only an instrument of the process; sometimes, indeed, exceedingly useful, and even indispensable, but never constituting the process itself, any more than laughter constitutes mirth, or a frown displeasure; or, to pass over to another class of illustrations, any more than shoes or sandals constitute walking, although they may help the walker; or than lenses constitute seeing, although without them we could not attain the sight of myriads of stars, which, to the unassisted eye, are hid in the depths of space.

The calculus which enabled Adams and Leverier to point out the spot in the heavens where an unknown planet was wheeling through its remote orbit, and the telescope through which Galle dis

covered it*, are both alike instruments by whose aid the natural faculties can reach to knowledge otherwise inaccessible, but which confer no new faculty on the intelligent agent who employs them.

It is generally understood that M. Galle of Berlin discovered the planet Neptune, Sept. 23. 1846, in consequence of a communication from M. Leverier.

CHAP. X.

THE RELATION OF OBSERVATION, EXPERIMENT, AND INDUCTION, TO REASONING AND TO EACH OTHER.

THE terms at the head of the present chapter denote closely allied and frequently intermingled operations, which it seems desirable to investigate, in order to show in what relation they stand to each other, and more particularly in what relation reasoning stands to the rest.

Experiment is usually placed in antithesis to observation, as if one excluded the other; but surely the intellectual act termed observation is just as much required for experiments as it is for spontaneous events. Unless experiments are observed, they can clearly be of no use. It is equally true, if not equally clear, that the observation of either spontaneous or experimental phenomena can scarcely take place without reasoning, and, if it could, would be of no scientific value.

To illustrate this by an example. We observe a stone fall rapidly to the ground, and a feather, floating in the atmosphere, slowly descend. Meditating on these events, we conjecture, or infer, that the air through which they fall has something to do with the difference in the rates of their descent. We, in consequence, devise the experi

I

ment (in which, also, reasoning is needful) of placing the two substances in a vessel exhausted of air; and we find that, on precipitating them from the same height, they come to the bottom of the vessel at the same moment. We try other substances with a similar result, and finally deduce the general law, that all substances at the surface of the earth descend in vacuo from equal heights in equal times.

There is evidently here, in the first place, observation of facts spontaneously occurring; then reasoning or conjecturing something from those facts, viz., what would result from withdrawing the element of air; further reasoning as to the mode of withdrawing it; acting on this reasoning by trying the experiment; subsequently making other experiments; and finally deducing a general conclusion, or law.

But, not only have we here observation of spontaneous and experimental phenomena with an intermixture of reasoning, but we have in those combined operations an example of what is usually termed induction. Induction is not some process superadded to those here described; but it is, in this instance, a combination of the two intellectual operations of observing and inferring, with the mechanical aid of experimental contrivances to enlarge their range, and for the purpose of deducing a general law.

It thus appears, that, instead of contrasting ob