Whether Descartes recommended a real or only a feigned doubt, as the first step in the scientific process he defended, has been and still is a disputed point. If it is only a feigned or pretended doubt, it is no real doubt at all, and he who affects it is a real believer all the time. It is a sham doubt, and we have never seen any good in science or in anything else come from shams or shamming. If the doubt is real, and is extended to all things, even to the being of God and our own existence, as Descartes recommends, we are at a loss to understand any process by which it can be scientifically removed. To him who really doubts of everything, even for a moment, nothing can be proved, for he doubts the proofs as well as the propositions to be proved. All proofs must be drawn either from facts or from principles, and none can avail anything with one who holds all facts and principles doubtful. The man who really doubts everything is out of the condition of ever knowing or believing anything. There is no way of refuting a sceptic but by directing his attention to something which he does not and cannot doubt; and if there is nothing of the sort, his refutation is impossible.
Descartes, according to The Churchman, when he declared he doubted the truth of everything, even of the existence of the sensible world and the being of God, did it in the interest of science, in order to find firm ground for his philosophical system. Doubt is ignorance, for no man doubts where he knows. So Descartes sought a firm ground for his philosophical system in universal ignorance! "He wished to stand upon (on) a principle which could not be denied, a first truth which no one could question." If he held there is such a principle, such a first truth, or anything which cannot be denied, he certainly did not and could not doubt of everything. If he doubted the being of God, how could he expect to find such a principle or such a first truth? The Churchman seems to approve of the Cartesian doubt, and says, "This philosophical scepticism is an essential element in all investigations of truth." If this real or feigned scepticism were possible, no investigations could end in anything but doubt, for it would always be possible, whatever the conclusions arrived at, to doubt them. But why can I not investigate the truth I do not doubt or deny?
Moreover, is it lawful, even provisionally, in the interest of science, to doubt, that is, to deny, the being of God? No man has the right to make himself an atheist even for a moment. The obligation to believe in God, to love, serve, and obey him, is a universal moral obligation, and binds every one from the first dawn of reason. To doubt the being of God is to doubt the whole moral order, all the mysteries of faith, the entire Christian religion. And does The Churchman pretend that any man in the interest of science or any other interest has the right voluntarily to do that?
Undoubtedly, every man has the right to interrogate "every accredited opinion" and to demand of it, "Have you any right to exist? are you a reality or a sham?" But the right to question "accredited opinions" is one thing, and the right to question the first principles either of science or of faith is another. A man has no more right voluntarily to deny the truth than he has to lie or steal. The Churchman will not deny this. Then either it holds that all science as all faith is simply opinion, or it deceives itself in supposing that it accepts the Cartesian doubt or adopts his philosophical scepticism. Doubt in the region of simple opinion is very proper. It would be perfectly right for The Churchman to doubt the opinion accredited among Protestants that Rome is a despotism, the papacy a usurpation, the Catholic religion a superstition, or that the church has lost, falsified, corrupted, or overlaid the pure Christian faith, and demand of that opinion, "Have you any right to exist? are you a reality or a sham?" And we have little doubt, if it would do so, that it would find itself exchanging its present opinion for the faith "once delivered to the saints." It is clear enough from the extract we have made that The Churchman means to justify scepticism only in matters of opinion, and that it is far enough from doubting of everything, or supposing that there is nothing real which no man can doubt.
But, if we examine a little more closely this Cartesian method which bids us doubt of everything till we have proved it, we shall find more than one reason for rejecting it. The doubt must be either real or feigned. If the doubt is only feigned for the purpose of investigation, it amounts to nothing, serves no purpose whatever; for every man carries himself with him wherever he goes, and enters into his thought as he is, with all the faith or science he really has. No man ever does or can divest himself of himself. Hence the difficulty we find even in imagining ourselves dead, for even in imagination we think, and in all thinking we think ourselves living, are conscious that we are not dead. In every thought, whatever else we affirm, we affirm our own existence, and this affirmation of our own existence is an essential and inseparable element of every thought. When I attempt to think myself dead, I necessarily think myself as surviving my own death, and as hovering over my own grave. No one ever thinks his own death as the total extinction of his existence, and hence we always think of the grave as dark, lonely, cold, as if something of life or feeling remained in the body buried in it. Men ask for proofs that the soul survives the dissolution of the body, but what they really need is proof that the soul dies. Life we know; but death, in the sense of total extinction of life, we know not; it is no fact of our experience. Life we can conceive, death we cannot. I am always living in my conceptions, and that I die with my body I am utterly unable to think, because I can think myself only as living.
The thinker, then, enters as an indestructible element into every one of his thoughts. Then he must enter as he is and for what he is. His real faith or science enters with him, and no doubt can enter that is not a real doubt. A feigned or factitious doubt, being unreal, does not and cannot enter with him. He is always conscious that he does not entertain it, and therefore can never think as he would if he did. The Christian, firm in his Christian faith, whose soul is clothed with Christian habits, cannot think as an infidel, or even in thought put himself in the infidel's position. Hence one reason why so many defences of Christianity, perfectly conclusive to the believer, fail of their purpose with the unbeliever. Even the unbeliever trained in a Christian community or bred and born under Christian civilization cannot think as one bred and born under paganism. What we assert is, that every man thinks as he is, and cannot think otherwise; simply what all the world means when it says of a writer, "Whatever else he writes, he always writes himself." Men may mimic one another, but always each in his own way. The same words from different writers produce not the same impression upon the reader. Something of himself enters into whatever a man thinks or does, and no translator has ever yet been able to translate an author from one language to another without giving something of himself in his translation. The Cartesian doubt, then, if feigned, factitious, or merely methodical, is impracticable, is unreal, and counts for nothing; for all along the investigator thinks with whatever faith and knowledge he really has; or simply, we cannot feign a doubt we do not feel.
It will be no better if we assume that the doubt recommended is real. No man really doubts what he does not doubt, and no man does or can doubt of everything; for even in doubt the existence of the doubter is affirmed. But suppose a man really does doubt of everything, the Cartesian method will never help him to resolve his doubts. From doubt you can get only doubt. To propose doubt as a method of philosophizing is simply absurd, as absurd as it would be to call scepticism philosophy, faith, or science. The mind that doubts of everything, if such a mind can be supposed, is a perfect blank, and, when the mind is a perfect blank, is totally ignorant of everything, how is it to understand, discover, or know that anything is or exists? There have indeed been men, sometimes men called philosophers, who tell us that the mind is at first a tabula rasa, or blank sheet, and exists without a single character written on it. If so, if it can exist in a state of blank ignorance, how can it, we should like to know, ever become an intelligent mind, or ever know anything more than the sheet of paper on which we are now writing? Intelligence can speak only to intelligence, and no mind absolutely unintelligent can ever be taught or ever come to know anything? But if we assume that the mind is in any degree intelligent, we deny that it can doubt of everything; for there is no intelligence where nothing is known, and what the mind knows it does not and cannot doubt. Either, then, this blank ignorance is impossible, or no intelligence is possible.
But, as we have already said, no man does or can doubt of everything, and hence the Cartesian method is an impossible method. Descartes most likely meant that we should doubt of everything, the external world, and even the being of God, and accept nothing till we have found a principle that cannot be denied, or a first truth that cannot be doubted, from which all that is true or real may be deduced after the manner of the geometricians. He did not mean to deny that there is such first truth or principle, but to maintain that the philosopher should doubt till he has found or obtained it. His error is in taking up the question of method before that of principles or first truths—an error common to nearly all philosophers who have succeeded him, but which we never encounter in the great Gentile philosophers, far less in the great fathers and mediaeval doctors of the church. These always begin with principles, and their principles determine their method. Descartes begins with method, and, as Cousin has justly said, all his philosophy is in his method. But, unhappily, his method, based on doubt, recognizes and conducts to no principles, therefore to no philosophy, to no science, and necessarily leaves the mind in the doubt in which it is held to begin. The discussion of method before discussing principles assumes that the mind is at the outset without principles, or, at least, totally ignorant of principles; and that, being without principles or totally ignorant of them, it is obliged to go forth and seek them, and, if possible, find or obtain them by its own active efforts. But here comes the difficulty, too often overlooked by our modern philosophers. The mind can neither exist nor operate without principles, or what some philosophers call first truths. The mind is constituted mind by the principles, and without them it is nothing and can do nothing. The supposed tabula rasa is simply no mind at all. Principles must be given, not found or obtained. We cannot even doubt without them, for doubt itself is a mental act, and therefore the principles themselves, without which no doubt or denial is possible, are not and cannot be denied or doubted; for even in denying or doubting the mind affirms them. Principles, again, cannot be given the mind without its possessing them, and for the mind to possess a thing is to know it. As the principles create or constitute the mind, the mind always knows them, and what it knows it does not and cannot doubt. The philosopher, as distinguished from the sophist, does not start from doubt, and doubt of everything till he has found something which he cannot doubt; but he starts from the principles themselves, which, being given, are nota per se, or self-evident, and therefore need no proof—in fact, are provable only from the absurd consequences which would follow their denial.