How much was comprehended in these enquiries.
One hundred years previously, the cautious reasoner, Descartes, instead of asking “What do we know?” posed in its place the question, “How do we know?”
This was in fact a fundamental question which appealed to philosophers who followed Descartes, as of the utmost importance, and they also asked themselves, “After what manner does the human mind acquire what it knows?”
What is called Locke’s tenet, “Nihil est in intellectu quod non ante fuerit in sensu,” Leibnitz answered by “Nihil—nisi intellectus.” Noiré gives this sentiment a fresh turn by saying: “There is nothing in this plant that was not already in the soil, the water and the atmosphere, but that which causes this plant to be a plant.”
Condillac, who agreed with Locke, thus formulated his opinion: “Penser c’est sentir”; or, “In order to feel it is necessary to possess senses,” which is self-evident.
Nevertheless, this sentence scandalised some of the philosophers, they considered it degraded thought. It degraded thought only in Condillac’s mouth, since he and his school had previously taken out of sentir or sensation all that possessed the right to be called thought; but for those who admit that sensation is really impregnated with thought it is no degradation; it is then true to say that thought is sensation, in the same way as an oak-tree may be said to be the acorn; and a little reflection will show us that “the acorn is far more wonderful than the oak, and perceiving far more wonderful than thinking.” This was not acknowledged by some who disagreed as to the nature of reason and sensation; they considered the former a mysterious power that could only be a direct gift of the Creator, and the senses, to which we owe our perceptions, appeared so natural and simple, as not to require a scientific explanation.
If philosophers, such as Descartes and Leibnitz, succeeded in influencing certain enlightened spirits, their language was not understood by the general public; and Berkeley’s idealism when pushed to the extreme point, proved too abstract to counterbalance the sensualist doctrines; its language hardly penetrated beyond the inner circle of the experts dealing with the subject, whereas the writings of Locke, Condillac and Hume permeated all classes of society; everywhere the same questions were asked, and often unanswered amidst the maze of metaphysics, in which it would have been difficult to obtain a precise explanation of a science not yet clearly defined.
It is natural that reason after its high flight in pursuit of truth, frightened by the obstacles met in its ascent, and by the contradictions found in itself, should fall heavily to earth, exclaiming with Voltaire, “O metaphysics, we are as advanced as in the times of the Druids.” This same feeling of distrust towards proceedings which resulted only in hypothesis, was also expressed by Newton, who, recognising that philosophy moved nowhere so freely nor with such certainty as in the domain of facts, recently cried, “O physics, preserve me from metaphysics.”
“Towards the end of the eighteenth century the current public opinion had been decidedly in favour of materialism, but a reaction was slowly setting in in the minds of independent thinkers when Kant appeared”; he came so exactly in the nick of time that one almost doubts whether the tide was turning, or whether he turned the tide.
To sketch briefly the chief points in Kant’s system such as he has given us in his book called Critique of Pure Reason, is a rash proceeding; my object, which is to satisfy the imperious and more immediate wants of our moral being, could only be attained by ignoring the irradicable difficulties; this is excusable if we, unlearned members of society, are to form any idea of this same philosophy.