Superiority of Descartes. 98. It was a matter of course that the vulnerable passages of the six Meditations would not escape the spear of so skilful an antagonist as Gassendi. But many of his objections appear to be little more than cavils; and upon the whole, Descartes leaves me with the impression of his great superiority in metaphysical acuteness. It was indeed impossible that men should agree, who persisted in using a different definition of the important word, idea; and the same source of interminable controversy has flowed ever since for their disciples. Gassendi adopting the scholastic maxim, “Nothing is in the understanding, which has not been in the sense,” carried it so much farther than those from whom it came that he denied anything to be an idea but what was imagined by the mind. Descartes repeatedly desired both him and Hobbes, whose philosophy was built on the same notion, to remark that he meant by idea, whatever can be conceived by the understanding, though not capable of being represented by the imagination.[241] Thus we imagine a triangle, but we can only conceive a figure of a thousand sides; we know its existence, and can reason about its properties, but we have no image whatever in the mind, by which we can distinguish such a polygon from one of a smaller or greater number of sides. Hobbes, in answer to this, threw out a paradox which he has not, at least in so unlimited a manner, repeated, that by reason, that is, by the process of reasoning, we can infer nothing as to the nature of things, but only as to their names.[242] It is singular that a man conversant at least with the elements of geometry should have fallen into this error. For it does not appear that he meant to speak only of natural substances, as to which his language might seem to be a bad expression of what was afterwards clearly shown by Locke. That the understanding can conceive and reason upon that which the imagination cannot delineate, is evident not only from Descartes’ instance of a polygon, but more strikingly by the whole theory of infinites, which are certainly somewhat more than bare words, whatever assistance words may give us in explaining them to others or to ourselves.[243]
[241] Par le nom d’idée, il veut seulement qu’on entende ici les images des choses matérielles dépeintes en la fantaisie corporelle; et cela étant supposé, il lui est aisé de montrer qu’on ne peut avoir propre et véritable idée de Dieu ni d’un ange; mais j’ai souvent averti, et principalement en celui là même, que je prends le nom d’idée pour tout ce qui est conçu immédiatement par l’esprit; en sorte que, lorsque je veux et que je crains, parce que je conçois en même temps que je veux et que je crains, ce vouloir et cette crainte sont mis par moi en nombre des idées; et je me suis servi de ce mot, parce qu’il étoit déjà communément reçu par les philosophes pour signifier les formes des conceptions. de l’entendement divin, encore que nous ne reconnoissions en Dieu aucune fantaisie ou imagination corporelle, et je n’en savois point de plus propre. Et je pense avoir assez expliqué l’idée de Dieu pour ceux qui veulent concevoir les sens que je donne à mes paroles; mais pour ceux qui s’attachent à les entendre autrement que je ne fais, je ne le pourrais jamais assez. Vol. i., p. 404. This is in answer to Hobbes; the objections of Hobbes, and Descartes’ replies, turn very much on this primary difference between ideas and images, which alone our countrymen could understand, and ideas as intellections, conceptions, νοουμενα, incapable of being imagined, but not less certainly known and reasoned upon. The French is a translation, but made by Clerselier under the eye of Descartes, so that it may be quoted as an original.
[242] Que dirons nous maintenant si peut-être le raisonnement n’est rien autre chose qu’un assemblage et un enchaînement de noms par ce mot est? D’ou 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, p. 476. Descartes merely answered:—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. Descartes treated Hobbes, whom he did not esteem, with less attention than his other correspondents. Hobbes could not understand what have been called ideas of reflection, such as fear, and thought it was nothing more than the idea of the object feared. “For what else is the fear of a lion,” he says, “than the idea of this lion, and the effect which it produces in the heart, which leads us to run away? But this running is not a thought; so that nothing of thought exists in fear but the idea of the object.” Descartes only replied, “it is self-evident that it is not the same thing to see a lion and fear him, that it is to see him only,” p. 483.
[243] I suspect, from what I have since read, that Hobbes had a different, and what seems to me a very erroneous view of infinite, or infinitesimal quantities in geometry. For he answers the old sophism of Zeno, Quicquid dividi potest in partes infinitas est infinitum, in a manner which does not meet the real truth of the case: Dividi posse in partes infinitas nihil aliud est quam dividi posse in partes quotcunque quis velit. Logica sive Computatio, c. 5., p. 38 (edit. 1667).
Stewart’s remarks on Descartes. 99. Dugald Stewart has justly dwelt on the signal service rendered by Descartes to psychological philosophy, by turning the mental vision inward upon itself, and accustoming us to watch the operations of our intellect, which, though employed upon ideas obtained through the senses, are as distinguishable from them as the workman from his work. He has given indeed to Descartes a very proud title, Father of the experimental philosophy of the human mind, as if he were to man what Bacon was to nature.[244] By patient observation of what passed within him, by holding his soul as it were an object in a microscope, which is the only process of a good metaphysician, he became habituated to throw away those integuments of sense which hide us from ourselves. Stewart has censured him for the paradox, as he calls it, that the essence of mind consists in thinking, and that of matter in extension. That the act of thinking is as inseparable from the mind as extension is from matter, cannot indeed be proved; since, as our thoughts are successive, it is not inconceivable that there may be intervals of duration between them; but it can hardly be reckoned a paradox. But whoever should be led by the word essence to suppose that Descartes confounded the percipient thinking substance, the Ego, upon whose bosom, like that of the ocean, the waves of perception are raised by every breeze of sense, with the perception itself, or even, what is scarcely more tenable, with the reflective action, or thought; that he anticipated this strange paradox of Hume in his earliest work, from which he silently withdrew in his Essays, would not only do great injustice to one of the acutest understandings that ever came to the subject, but overlook several clear assertions of the distinction, especially in his answer to Hobbes. “The thought,” he says, “differs from that which thinks, as the mode from the substance.”[245] And Stewart has in his earliest work justly corrected Reid in this point as to the Cartesian doctrine.[246]
[244] Dissertation on Progress of Philosophy. The word experiment must be taken in the sense of observation. Stewart very early took up his admiration for Descartes. “He was the first philosopher who stated in a clear and satisfactory manner the distinction between mind and matter, and who pointed out the proper plan for studying the intellectual philosophy. It is chiefly in consequence of his precise ideas with respect to this distinction, that we may remark in all his metaphysical writings, a perspicuity which is not observable in those of any of his predecessors.” Elem. of Philos. of Human Mind, vol. i. (published in 1792) note A. “When Descartes,” he says in the dissertation before quoted, “established it as a general principle that nothing conceivable by the power of imagination could throw any light on the operations of thought, a principle which I consider as exclusively his own, he laid the foundations of the experimental philosophy of the human mind. That the same truth had been previously perceived more or less distinctly by Bacon and others, appears probable from the general complexion of their speculations; but which of them has expressed it with equal precision, or laid it down as a fundamental maxim in their logic?” The words which I have put in italics seem too vaguely and not very clearly expressed, nor am I aware that they are borne out in their literal sense, by any position of Descartes; nor do I apprehend the allusion to Bacon. But it is certain that Descartes, and still more his disciples Arnauld and Malebranche, take better care to distinguish what can be imagined from what can be conceived or understood, than any of the school of Gassendi in this or other countries. One of the great merits of Descartes as a metaphysical writer, not unconnected with this, is that he is generally careful to avoid figurative language in speaking of mental operations, wherein he has much the advantage over Locke.
[245] Vol. i., p. 470. Arnauld objected, in a letter to Descartes, Comment se peut il faire que la pensée constitue l’essence de l’esprit, puisque l’esprit est une substance, et que la pensée semble n’en être qu’un mode? Descartes replied that thought in general, la pensée, ou la nature que pense, in which he placed the essence of the soul, was very different from such or such particular acts of thinking, vol. vi., p. 153-160.
[246] Philosophy of Human Mind, vol. i., note A. See the Principia, § 63.
Paradoxes of Descartes. 100. Several singular positions which have led to an undue depreciation of Descartes in general as a philosopher, occur in his metaphysical writings. Such was his denial of thought, and, as is commonly said, sensation to brutes, which he seems to have founded on the mechanism of the bodily organs, a cause sufficient, in his opinion, to explain all the phænomena of the motions of animals, and to obviate the difficulty of assigning to them immaterial souls;[247] his rejection of final causes in the explanation of nature, as far above our comprehension, and unnecessary to those who had the internal proof of God’s existence; his still more paradoxical tenet that the truth of geometrical theorems, and every other axiom of intuitive certainty, depended upon the will of God; a notion that seems to be a relic of his original scepticism, but which he pertinaciously defends throughout his letters.[248] From remarkable errors, men of original and independent genius are rarely exempt; Descartes had pulled down an edifice constructed by the labours of near two thousand years, with great reason in many respects, yet perhaps with too unlimited a disregard of his predecessors; it was his destiny, as it had been theirs, to be sometimes refuted and depreciated in his turn. But the single fact of his having first established, both in philosophical and popular belief, the immateriality of the soul, were we even to forget the other great accessions which he made to psychology, would declare the influence he has had on human opinion. From this immateriality, however, he did not derive the tenet of its immortality. He was justly contented to say that from the intrinsic difference between mind and body, the dissolution of the one could not necessarily take away the existence of the other, but that it was for God to determine whether it should continue to exist; and this determination, as he thought, could only be learned from his revealed will. The more powerful arguments, according to general apprehension, which reason affords for the sentient being of the soul after death, did not belong to the metaphysical philosophy of Descartes, and would never have been very satisfactory to his mind. He says, in one of his letters, that “laying aside what faith assures us of, he owns that it is more easy to make conjectures for our own advantage and entertain promising hopes, than to feel any confidence in their accomplishment.”[249]
[247] It is a common opinion that Descartes denied all life and sensibility to brutes. But this seems not so clear. Il faut remarquer, he says in a letter to More, where he has been arguing against the existence in brutes of any thinking principle, que je parle de la pensée, non de la vie, ou du sentiment; car je n’ôte la vie à aucun animal, ne la faisant consister que dans la seule chaleur du cœur. Je ne leur refuse pas même le sentiment autant qu’il dépend des organes du corps, vol. x., p. 208. In a longer passage, if he does not express himself very clearly, he admits passions in brutes, and it seems impossible that he could have ascribed passions to what has no sensation. Much of what he here says is very good. Bien que Montaigne et Charron aient dit, qu’il y a plus de différence d’homme à homme que d’homme à bête, il n’est toutefois jamais trouvé aucune bête si parfaite, qu’elle ait usé de quelque signe pour faire entendre à d’autres animaux quelque chose que n’eût point de rapport à ses passions; et il n’y a point d’homme si imparfait qu’il n’en use; en sorte que ceux qui sont sourds et muets inventent des signes particuliers par lesquels ils expriment leur pensées; ce qui me semble un très fort argument pour prouver que ce qui fait que les bêtes ne parlent point comme nous, est qu’elles n’ont aucune pensée, et non point que les organes leur manquent. Et on ne peut dire qu’elles parlent entre elles, mais que nous ne les entendons pas; car comme les chiens et quelques autres animaux nous expriment leurs passions, ils nous exprimeroient aussi bien leurs pensées s’ils en avoient. Je sais bien que les bêtes font beaucoup de choses mieux que nous, mais je ne m’en étonne pas; car cela même sert à prouver qu’elles agissent naturellement, et par ressorts, ainsi qu’un horloge; laquelle montre bien mieux l’heure qu’il est, que notre jugement nous l’enseigne.... On peut seulement dire que, bien que les bêtes ne fassent aucune action qui nous assure qu’elles pensent, toutefois, à cause que les organes de leurs corps ne sont pas fort differens des nôtres, on peut conjecturer qu’il y a quelque pensée jointe à ces organes, ainsi que nous experimentons en nous, bien que la leur soit beaucoup moins parfaite; à quoi je n’ai rien à répondre, si non que si elles pensoient aussi que nous, elles auroient une ame immortelle aussi bien que nous; ce qui n’est pas vraisemblable, à cause qu’il n’y a point de raison pour le croire de quelques animaux, sans le croire de tous, et qu’il y en a plusieurs trop imparfaits pour pouvoir croire cela d’eux, comme sont les huitres, les éponges, &c. Vol. ix., p. 425. I do not see the meaning of une ame immortelle in the last sentence; if the words had been une ame immortelle, it would be to the purpose. More, in a letter to which this is a reply, had argued as if Descartes took brutes for insensible machines, and combats the paradox with the arguments which common sense furnishes. He would even have preferred ascribing immortality to them, as many ancient philosophers did. But surely Descartes, who did not acknowledge any proofs of the immortality of the human soul to be valid, except those founded on revelation, needed not to trouble himself much about this difficulty.