The Divine Lamp

Article1.  various aspects of the difficulty.

134.  As I have already observed, all the principal philosophers have fallen on the difficulty so often mentioned, as upon a rock standing in the way, so to speak, of their philosophical course.

It has always been so in the solution of great problems.  A great problem is nothing but a great difficulty to be overcome.  Now, we must not imagine that in the proposing of difficulties a philosopher has his own free choice, as though he knew or surmised them all beforehand, and could take up for consideration whichever of them he pleased.  If difficult problems have been solved only after the lapse of many ages, this arose not so much from the greatness of the difficulty involved in them, as from the circumstance that they were not known.  It may be said with truth, that a difficulty once brought under the notice of men is already half solved, and that it is sometimes brought under the notice of the learned by a mere accident.  This we see, for instance, in the case of oscillations of Galileo’s lamp, to which mathematical science owes its theory on isochronous arcs; and in that of the falling of the apple, which resulted in Newton’s system of universal gravitation.

But it is not sufficient that the difficulties be seen in any sort of way.  To be solved aright, they must be seen aright.  The tardiness of their solution is in great part to be attributed to the length of time which must elapse before the state of the question can be presented to the student with simplicity and fulness, so that he may look at it, not merely sideways, on occasion of his thinking of some other thing, but straight in the face.

This is precisely what has happened in reference to our difficulty.  Thrown in the path of nearly all philosophers, it was nevertheless lightly passed over by them, because they had not made it the direct object of their inquiries; while the greater number of them saw it only in a confused way and under an accidental form.

I take note of this in order that I may deal fairly by those authors; for it seems nothing but equitable to believe, that, had they only been able to put the difficulty to themselves as clearly as we now can, thanks to the labors which they accomplished, and of which we reap the benefit, they would have solved it quite as well as we.

135.  To recapitulate, then, the various accidents which have placed our difficulty in the way of modern philosophers:-

Locke stumbled upon it when obliged to speak of the idea of substance, and also when coming to define the term knowledge-he perceived that he could not define it without having recourse to judgments.  Condillac came very close to it when he had to distinguish ideas from sensations, and to treat of general ideas.   Reid did the same thing while seeking to account for the persuasion we have of the existence  of external bodies; for he then discovered that Locke had erred in making the  development of the human mind begin with acquired ideas, and that the acquisition of ideas presupposed an original and natural judgment.  And how was the difficulty seen y the late Dugald Stewart, who had been in his time the mainstay of the meritorious Scottish school?  He also went very near  it, though not near enough to  see it clearly.  This was on the occasion of his trying to explain how general ideas can  be formed through the imposition of names to things.  Let us examine carefully how it faired with him.

Article 2.  Dugald Stewart Grounds His Theory On A Passage Of Adam Smith.

136.  In that chapter of his ELEMENTS OF THE PHILOSOPHY OF THE HUMAN MIND where he undertakes to treat of the faculty of abstraction, Dugald Stewart quotes a passage from the DISSERTATION ON THE ORIGIN OF LANGUAGE, by Adam Smith, which as it contains the principal idea of his theory on abstraction, I shall insert here.

• •  ”The assignation of particular names to denote particular objects- that is, the institution of nouns substantive-would probably be one of the first steps towards the formation of language.  The particular cave whose covering sheltered the savage from the weather; the particular tree whose fruit relieved his hunger; the particular fountain whose water allayed his thirst, would first be denominated by the words cave, tree, fountain, or by whatever other appellations he might think proper, in that primitive jargon, to mark them.   Afterwards, when the more enlarged experience of this savage had led him to observe, and his necessary occasions obliged him to make mention of, other caves, and other trees, and other fountains, he would naturally bestow upon each one of those new objects the same name y which he had been accustomed to express the similar object he was first acquainted with.  And thus those words, which were originally the proper names of individuals, would each of them insensibly become the common name of a multitude.
  • “It is this application,” continues Smith, “of the name of an individual to a great number of objects whose resemblance naturally recalls the idea of that individual and of the name which expresses it, that seems originally to have given occasion to the formation of those classes and assortments, which in the schools are called genera and species, and of which the ingenious and eloquent Rousseau finds himself so much at a loss to account for the origin.  What constitutes a species is merely a number of objects bearing a certain degree of resemblance to one another, and on that account denominated by a single appellation, which may be applied to express one of them.” (Chapter 4, sec 1)

137.  This mode of explaining how the ideas of genera and species are formed, seems at first sight very easy and natural.  But if we diligently search into it we shall find that the explanation, its plausibility notwithstanding, is no better than an illusion.  I look upon it as one of those explanations which, owing to the seductively elegant form in which they are presented, divert the minds of unwary readers from things contained in it.  Being charmed with the pleasing smoothness with which the argument seems to proceed, these readers do not think it necessary to verify for themselves what is said, but confidingly take its truth for granted.  As regards myself, however, having been taught by a painful experience that under reasonings of the most plausible kind there often lie errors pregnant with numerous evil consequences, I must be forgiven if, before accepting the reasoning above quoted, I consider it my right as well as my duty to scan carefully.