Another royal friendship brought his career to an untimely end. Queen Christina of Sweden, the gifted and restless daughter of Gustavus Adolphus, heard of Descartes, and invited him to her Court. On his arrival she sent for the pilot who had brought the illustrious stranger to Stockholm and questioned him about his passenger. "Madame," he replied, "it is not a man whom I conducted to your Majesty, but a demi-god. He taught me more in three weeks of the science of seamanship and of winds and navigation than I had learned in the sixty years I had been at sea" (Miss E. S. Haldane's Life of René Descartes). The Queen fully came up to the expectations of her visitor, in whose eyes she had no fault but an unfortunate tendency to waste her time on learning Greek. Besides her other merits, she possessed "a sweetness and goodness which made men devoted to her service." It soon appeared that, as with others of the same rank, this was only the veneer of a heartless selfishness. Christina, who was an early riser, required his attendance in her library to give her lessons in philosophy at five o'clock in the morning. Descartes was by habit a very late riser. Besides, he had not even a lodging in the royal palace, but was staying at the French Embassy, and in going there "had to pass over a long bridge which was always bitterly cold." The cold killed him. He had arrived at Stockholm in October, and meant to leave in January; but remained at the urgent request of the Queen, who, however, made no change in the hour of their interviews, although that winter was one of the severest on record. At the beginning of February, 1650, he fell ill and died of inflammation of the lungs on the 11th, in the fifty-fourth year of his age.
Descartes had the physical courage which Hobbes lacked; but he seems, like Bacon, to have been a moral coward. The most striking instance of this is that, on hearing of Galileo's condemnation for teaching the heliocentric astronomy, he withheld from publication and had even thoughts of destroying a work of his own in which the same doctrine was maintained. This was at a time when he was living in a country where there could be no question of personal danger from the Inquisition. But something of the same weakness shows itself in his running away from France to escape those intrusions on his studious retirement which one would think might have been checked by letting it be known with sufficient firmness that his hours could not be wasted on idle conversation. And we have seen how at last his life was lost for no better reason than the dread of giving offence to Queen Christina.
It seems strange that a character so unheroic should figure among the great emancipators of human thought. In fact, Descartes's services to liberty have been much exaggerated. His intellectual fame rests on three foundations. Of these the most indubitable is the creation of analytical geometry, the starting-point of modern mathematics. The value of his contributions to physics has been much disputed; but, on the whole, expert opinion seems to have decided that what was new in them was not true, and what was true was not new. However, the place we must assign Descartes in the history of philosophy can only be determined by our opinion of his metaphysics.
As a philosopher Descartes has, to begin with, the merit of exemplary clearness. The fault is not with him if we cannot tell what he thought and how he came to think it. The classic Discourse on Method (1637) relates his mental history in a style of almost touching simplicity. It appears that from an early age truth had been his paramount object, not as with Bacon and Hobbes for its utility, but for its own sake. In search of this ideal he read widely, but without finding what he wanted. The great and famous works of literature might entertain or dazzle; they could not convince. The philosophers professed to teach truth; their endless disputes showed that they had not found it. Mathematics, on the other hand, presented a pleasing picture of demonstrated certainty, but a certainty that seemed to be prized only as a sure foundation for the mechanical arts. Wearily throwing his books aside, the young man then applied himself to the great book of life, mingling with all sorts and conditions of men to hear what they had to say about the prime interests of existence. But the same vanity and vexation of spirit followed him here. Men were no more agreed among themselves than were the authorities of his college days. The truths of religion seemed, indeed, to offer a safe refuge; but they were an exception that proved the rule; being, as Descartes observes, a supernatural revelation, not the natural knowledge that he wanted.
The conflict of authorities had at least one good result, which was to discredit the very notion of authority, thus throwing the inquirer back on his own reason as the sole remaining resource. And as mathematics seemed, so far, to be the only satisfactory science, the most reasonable course was to give a wider extension and application to the methods of algebra and geometry. Four fundamental rules were thus obtained: (1) To admit nothing as true that was not evidently so; (2) to analyse every problem into as many distinct questions as the nature of the subject required; (3) to ascend gradually from the simplest to the most complex subjects; and (4) to be sure that his enumerations and surveys were so exhaustive and complete as to let no essential element of the question escape.
The rules as they stand are ill-arranged, vague, and imperfect. The last should come first and the first last. The notions of simplicity, complexity, and truth are neither illustrated nor defined. And no pains are taken to discriminate judgments from concepts. It may be said that the method worked well; at least Descartes tells us that with the help of his rules he made rapid progress in the solution of mathematical problems. We may believe in his success without admitting that an inferior genius could have achieved the same results by the same means. The real point is to ascertain whether the method, whatever its utility in mathematics, could be advantageously applied to metaphysics. And the answer seems to be that as manipulated by its author the new system led to nothing but hopeless fallacies.
After reserving a provisional assent to the customs of the country where he happens to be residing and to the creed of the Roman Church, Descartes begins by calling in question the whole mass of beliefs he has hitherto accepted, including the reality of the external world. But the very act of doubt implies the existence of the doubter himself. I think, therefore I am. It has been supposed that the initial affirmation of this self-evident principle implies that Descartes identified Being with Thought. He did no such thing. No more is meant, to begin with, than that, whatever else is or is not, I the thinker certainly am. This is no great discovery; the interesting thing is to find out what it implies. A good deal according to Descartes. First he infers that, since the act of thinking assures him of his existence, therefore he is a substance the whole essence of which consists in thought, which is independent of place and of any material object – in short, an immaterial soul, entirely distinct from the body, easier to know, and capable of existing without it. Here the confusion of conception with judgment is apparent, and it leads to a confusion of our thoughts about reality with the realities themselves. And Descartes carries this loose reasoning a step further by going on to argue that, as the certainty of his own existence has no other guarantee than the clearness with which it is inferred from the fact of his thinking, it must therefore be a safe rule to conclude that whatever things we conceive very clearly and distinctly are all true.