Hume vs. Descartes in Skepticism

In part 1 of Section 2 of An Inquiry Concerning Human Understanding, Hume talks about two kinds of skepticism, antecedent and consequent skepticisms. The first kind is known as the cartesan doubt which serves as "a sovereign preservative against error and precipitate judgment." The latter kind is known as consequent skepticism that is against the evidence of sense and is derived from the imperfection and fallaciousness of our organs such as: the crooked appearance of an oar in water, the various aspects of objects according to their different distances, the double images which arise from pressing one eye, etc. To Hume, the first kind "were it ever possible to be attained by any human creature (as it plainly is not) woulf be entirely incurable and no reasoning could ever bring us to a state of assurance and conviction upon any subject." And "it recommends a universal doubt not only of all our former opinions and principles, but also of our very faculties. But neither is there any such original principle which has a prerogative above others that are self-evident and convincing. Or if there were," he opposes, "could we advance a step beyond it by the use of those very faculties of which we are supposed to be already diffident?" For the second kind, there are a lot of questions that Hume asks to check to see whether they are good skepticisms. Hume says, "it seems evident that men are carried by a natural instinct or propossession to repose faith in their senses, and that without any reasoning, or even almost before the use of reason, we always suppose an external uiverse which does not depend on our perception, but would exist though we and every sensible creature were absent or annihilated." What he means is that our senses present the natural things around to us and we cannot recognize or know natural thing without senses, and that our senses are our foremost and closest teachers of our knowledge. Hume says,


This very table which we see white and which we feel hard is believed to exist independent of our perception and to be something external to our mind which perceives it. Our presence does not bestow being on it. Our absence does not annihilate it. Its preserves its existence uniform and entire, independent of the situation of intelligent beins who perceive or contemplate it. (551)


Of the second kind of skepticism, Hume says, there is another skeptical topic of the like nature that is derived from the most profound philosophy which - I think, he implies Berkeley's immeterialism - "might merit our attention were it requisite to dive so deep in order to discover arguments and reasonings which can so little serve to any serious purpose. It is universally allowed by modern inquirers that all the sensible qualities of objects, such as hard, soft, hot, cold, white, black, etc. are merely secondary and do not exist in the objects themselves, but are perceptions of the mind, without any external archetype or model which they represent... or can the latter be any more entitled to that denomination than the former." (552) To this skeptical topic, Hume opposes with the following comments:


Nothing can save us from this conclusion but asserting that the ideas of those primary qualities are attained by abstraction, an opinion which, if we examine it accurately, we shall find to be unintelligible and even absurd. An extension that is neither tangible nor visible cannot possibly be conceived, and a tangible or visible extension which is neither hard nor soft, black nor white, is equally beyond the reach of human conception. (552)


To give a final conclusion about these two main skepticisms. Hume writes:


The first philosophical objection to the evidence of sense or to the opinion of external existence consists in this, that such an opinion, if rested on natural instinct, is contrary to reason, if referred to reason, is contrary to natural instince and at the same time carries no rational evidence with it to convince an impartial inquirer. The second objection goes further and represents this opinion as contrary to reason, at least, if it is a principle of reason that all sensible qualities are in the mind, not in the subject. Deprive matter of all its intelligible qualities, both primary and secondary, you in a manner annihilate it and leave only a certain unknown, inexplicable something as the cause of our perceptions - a notion so imperfect that no skeptic will think it worthwhile to contend against it. (553)


In part II of section 12, Hume classifies skepticisms into another two main kinds, the first kind that "is against all abstract reasoning" and the second kind that are "skeptical objections to moral evidence or to the reasonings concerning matter of fact." To the first kind, Hume says,


No priestly dogmas invented on purpose to tame and subdue the rebellious reason of mankind ever shocked common sense more than the doctrine of infinite divisibility of extension, with its consequences as they are pompously displayed by all geometers and metaphysicians with a kind of triumph and exultation. A real quantity, containing quantity, infinitely less than any finite quantity, containing quantities infinitely less than itself, and so on in infinitum; this is an edifice so bold and prodigious that it is too weighty for any pretended demonstration to support because it shocks the clearest and most natural principles of human reason. But what renders the matter more extraordinary is that these seemingly absurd opinions are supported by a chain of reasoning, the clearest and mast natural, nor is it possible for us to allow premises without admitting the consequences. (553)


To respond to these abstract reasonings derived from the ideas of space and time, Hume writes:


Reason here seems to be thrown into a kind of amazement and suspense which without the suggestions of any skeptic, gives her a diffidence of herself and of the ground on which she treads. She sees a full light illuminates certain places, but that light borders upon the most profound darkness. (553)


To the second kind, Hume says, "the skeptical objections to moral evidence or to the reasonings concerning matter of fact are either popular or philosophical." And the popular objections "are derived from the natural weakess of human understanding: the contradictory opinions which have been entertained in different ages and nations; the perpetual contradiction of each particular man's opinions and sentiments with many other topics of that kind." (554) And "these principles may flourish and triumph in the schools, where it is indeed difficult, if not impossible, to refute them. But as soon as they leave the shade and by the presence of the real objects which actuate our passions and sentiments are put in opposition to the more powerful principles of our nature, they vanish like smoke and leave the most determined skeptic in the same condition as other mortals." (554)


In part 3, Hume talks about "a more mitigated skepticism or academic philosophy which may be both durable and useful and which may, in part, be the result of this Pyrrhonism or excessive skepticism when its undistinguished doubts are in some measure corrected by common sense and reflection." (555) He says additionally, "In general, there is a degree of doubt and caution and modesty which, in all kinds of scrutiny and decision, ought forever accompany a just reasoner." And "A correct judgment observes a contrary method, and avoiding all distant and high inquiries, confines itself to common life and to such subjects as fall under daily experience..." Hume means taht this type of academic philosophy agrees with his central ideas presented in previous sections that are relevant to main ideas such as life experiences and examinations, custome and habits, causes and effects as matters of facts, etc. To defend for this type of mitigated skepticism, Hume returns to his former ideas as stated in the above sentence in the following comments:


No negation of a fact can involve a contradiction. The nonexistence of any being, without exeption, is as clear and distinct an idea as its existence. The proposition which affirms it not be, however false, is no less conceivable and intellible than that which affirms it to be. The case is different with the sciences, properly so called. Every proposition which is not true is there confused and unintelligible. That the cube rood of 64 is equal to the half of 10 is a false propostion and can never be distincly conceived. But that Caesar, or the angel Gabriel, or any being never existed may be a false proposition, but still it perfectly conceivable, and implies no contradiction. The existence, therefore, of any being can only be proved by arguments from its cause or its effect and these arguments are founded entirely on experience. If we reason a priori, anything may appear able to produce anything. The falling of a pebble may, for all we know, extinguish the sun or the wish of a man control the planets in their orbits. It is only experience which teaches us the nature and bounds of cause and effect and enables us to infer the existence of one object from that of another. (556)


Hume concludes that all moral reasonings are either concerning particular or general facts. Sciences consider general facts; the divinity or theology is composed partly of reasonings concerning particular, partly concerning general facts; even beauty whether moral or natural, is felt more properly than perceived. Morals and criticism are not so properly objects of the understanding as of taste and sentiment, but all of those area that are inclined towards senses and life experiences - by his own term 'facts' - more than perceptions in the minds are what Hume stands for and trusts in order to prove for their true existence.


As I said above that Hume's central theory focuses on facts and experiences, mitigated skepticism that brings us to "so salutary a determination, nothing can be more serviceable than to be once thoroughly convinced of the force of the Pyrrhonian doubt and of the impossibility that anything but the strong power of natural instinct could free us from it." I think, Hume is right that his mitigated skepticism is an improvement over the excessive skepticism of philosophers like Descartes because as Hume says previously that: "The existence of any being can only be proved by arguments from its cause or its effect and these arguments are founded entirely on experience." And this statement is against the method of rationalism on which Descartes emphasizes as the best method over senses and impressions which Descartes thinks can put him into dreams and imaginations - the subjects that Hume are taking to be his central objects to prove for the existence of natural things.





Rerferences


Hume, David. "An Inquiry Concerning Human Understanding", Modern Philosophy: An Athology of Primary Sources. Eds. Roger Ariew and Eric Watkins. Indianapolis: Hackett Publishing Company, 1998. 491-557.