Compare and Contrast Descarte’s Rationalism and Hume’s Empiricism
Compare and Contrast Descarte's Rationalism and Hume's Empiricism
One of the fundamental differences between rational and empirical philosophers concerns their epistemologies. Since the classical era of Plato and Aristotle, such queries, regarding the capacity and constituents of human knowledge, have been prevalent in philosophy. This was equally, if not more, the case for philosophers of the classical modern school: Descartes, Spinoza, Locke, Hume, and Kant, amongst others. The purpose of this essay is to compare and contrast the rationalism and empiricism of two such philosophers - Descartes and Hume, respectively. This will be achieved predominantly through an analysis of the aforementioned epistemologies, although other related issues, such as skeptism, will also be taken into consideration.
The Oxford Companion to Philosophy defines rationalism as:
"Any of a variety of views emphasizing the role of importance or reason,
usually including intuition, in contrast to sensory experience
(including introspection), the feelings, or authority." 1
Whilst this definition inevitably applies to rationalism in the broadest sense of the term, it is nevertheless applicable to Cartesian ideas. In his Meditations I and II, Descartes, attempting to discover which of the principles he calls 'knowledge' are absolute truths, systematically examines and rejects that which he has previously held to be true. Anything which he has found to be false in the past, he discards, even to the extent of discounting all sensory evidence, on the basis that he has previously been deceived by his senses, and therefore may be fooled by them again. The conclusion of this process of doubt is that Descartes isolates the one thing which he holds to be an a priori truth. He writes:
"...having thought carefully about it, and having scrupulously examined everything,
one must then, in conclusion, take as assured the proposition: I am, I exist,
is necessarily true, every time I express it or conceive of it in my mind." 2
This belief in the existence of innate ideas is the main cause of diversity between rational and empirical epistemologies. In order to recognise this diversity, it is worth, at this point, considering the definition of empiricism:
"Any view which bases our knowledge, or the materials from which it is constructed, on
experience through the traditional five senses... Empiricism has its roots in the idea
that all we can know about the world is what the world cares to tell us; we must observe
it neutrally and dispassionately, and any attempt on our part to mould or interfere
with the process of receiving this information can only lead to distortion and arbitrary
imagining. This gives us a picture of the mind as a blank tablet (tabula rasa) on
which information is imprinted by the senses in the form of 'sense-data'." 3
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experience through the traditional five senses... Empiricism has its roots in the idea
that all we can know about the world is what the world cares to tell us; we must observe
it neutrally and dispassionately, and any attempt on our part to mould or interfere
with the process of receiving this information can only lead to distortion and arbitrary
imagining. This gives us a picture of the mind as a blank tablet (tabula rasa) on
which information is imprinted by the senses in the form of 'sense-data'." 3
It can be seen, through the two above definitions, that rationalists believe that the bases of knowledge are a priori truths, which are instinctively known, and are neither obtained through the senses or through the evaluation of sense-data; empiricists purport that all knowledge is intrinsically obtained through experience. Hume explains that knowledge is obtained in the form of ideas and impressions:
"All the perceptions of the human mind resolve themselves into two distinct kinds,
which I shall call impressions and ideas. The difference between these consists in the
degrees of force and liveliness with which they strike upon the mind, and make their
way into our thought or consciousness. Those perceptions which enter with most force
and violence, we may name impressions; and, under this name, I comprehend all our
sensations, passions, and emotions, as they make their first appearance in the soul.
By ideas, I mean the faint images of these in thinking and reasoning; such as, for instance,
are all the perceptions excited by the present discourse, excepting those which arise from
the sight and touch, and excepting the immediate pleasure or uneasiness it may occasion." 4
Hume also states that ideas and impressions can take two forms - simple, or complex. He writes:
"Simple perceptions, or impressions and ideas, are such as admit of no distinction nor
separation. The complex are the contrary to these, and may be distinguished into parts." 5
Hume continues by using the example of an apple as a complex impression - although the colour, taste and smell of the apple are united to create our impression of the apple, they can easily be distinguished from each other and stand alone as simple impressions or ideas - such as the idea of something being 'apple-coloured'.
One thing which Hume refuses to concede is the existence of any form of knowledge more basic than a simple idea or impression. In his Enquiry Concerning Human Understanding, he asserts that only through the relation of "cause and effect" can we "go beyond the evidence of our memory and senses", adding:
"I shall venture to affirm, as a general proposition, which admits of no exception, that the
knowledge of this relation [of "cause and effect"] is not, in any instance, attained by
reasonings a priori; but arises entirely from experience..." 6
To consider the existence of innate truths would be to engage in metaphysical speculation, something which Hume holds as being utterly pointless. This is due to the fact that, because it can never be anything more than speculation, whether experience or rational argument are employed, it is impossible to gain knowledge in this area. (However, Hume at no point says that it is meaningless to speak of, or hold beliefs about, such things.) In strict contrast, Descartes - whose Meditations lead him to assert that a priori truths are the bases of knowledge - frequently engages in metaphysical speculation, and comes to conclusions about the fundamentals of knowledge as a result of this hypothesis. It is Hume's skeptism in this area that makes him known as an empiricist; similarly, Descartes' belief in innate knowledge defines him as a rationalist.
Although Descartes and Hume are so opposed in terms of their epistemologies, they do share some philosophical traits. A notable example is that of their skepticism. When searching for the foundations of human knowledge, both employ the same kind of skepticism, methodically doubting the existence of previously assumed truths outside the mind. Each realises that nothing outside the mind can ever be indubitable - although later, they put forward different theories concerning the attainment of knowledge. By addressing the problem of skepticism by treating it as a theoretical problem, both Hume and Descartes - the latter especially - manage to control their skepticism, unlike the classical skeptics before them. These feel prey to epoche, the suspense of judgment, through frequently finding themselves unable to resolve philosophical arguments. Hume demonstrates another form of skepticism when he predicates that materialism and immaterialism are equally impossible positions to hold, because neither can back up its own arguments. Because he believes that it is equally out of the question either to verify or disprove that anything exists outside the mind, stating that we can never be directly aware of anything outside our own thoughts, he has to be content with suspending his certainty with regards to this.
Descartes also becomes accustomed to suspending his judgement on various ideas, though not for the same reason - rather, one the inverse of Hume's. He realises that it is possible to argue both sides of a dispute with arguments similarly persuasive. Interestingly, Descartes, though very much rationalist in terms of his philosophical thinking, was also an experimentalist. In his pursuit of biology and optics, in particular, he argued that knowledge rests upon experience and experimentation - so in this respect, too, his attitude is not so far removed from Hume's.
As in their epistemologies, Descartes and Hume differ greatly in their sentiments towards philosophy in general. Hume, succeeding Descartes, does not attach great significance to their subject due to the importance of either Cartesian doubt (he disagrees with Descartes' conclusion, and does not think it plausible), or an increased awareness of metaphysical knowledge. He does not feel that rational knowledge is important to life to the extent that Descartes does - he is content to rely upon instinct, as he survived this way before doubting the evidence of his senses.
In conclusion, Descartes and Hume, although contemporaries in the history of philosophy, belong to very different schools of thought. Their epistemologies dictate whether they are termed rationalist or empiricist, and these are very diverse. Even in terms of attitude towards philosophy as a subject, they cannot agree. However, two salient points should be noted. First, although Descartes' and Hume's philosophies differ drastically in many ways, there are also areas in which their thoughts correspond - for example, their skepticism. Second, it is worth considering that the differences between the thinking of Hume and Descartes do not necessarily hold true if rationalism and empiricism in general are being compared. This is because both philosophers represent their relevant schools of thought in extreme forms - Hume is very much an empiricist, Descartes very much a rationalist. Other philosophers, with less radical views, have nevertheless been defined as being rationalist or empiricist - for example, few rationalists would go so far as to invent an malevolent deity to explain how humans could be deceived in everything they do or believe, but this is what Descartes does in his Meditation I. However, the exercise of identifying the differences between Descartes' and Hume's persuasions is useful in emphasizing the differences between two of the predominant philosophical schools: rationalism, and empiricism.
FOOTNOTES
. Honderich, Ted (edited by). The Oxford Companion to Philosophy: Oxford University Press, 1995
2. Descartes, René. Discourse on Method and the Meditations: tr F.E. Sutcliffe, Penguin Books 1968
(Pg. 105)
3. Honderich, Ted (edited by). The Oxford Companion to Philosophy: Oxford University Press, 1995
4. Hume, David. A Treatise of the Human Nature. Cited in: Ayer, A.J. and Winch, Raymond (edited by). British Empirical Philosophers: Routledge and Kegan Paul Ltd, 1952 (Pg. 298)
5. Hume, David. A Treatise of the Human Nature. Cited in: Ayer, A.J. and Winch, Raymond (edited by). British Empirical Philosophers: Routledge and Kegan Paul Ltd, 1952 (Pg. 299)
6. Hume, David. An Enquiry Concerning Human Understanding. Cited in: Ayer, A.J. and Winch, Raymond (edited by). British Empirical Philosophers: Routledge and Kegan Paul Ltd, 1952 (Pg. 505)
BIBLIOGRAPHY
* Ayer, A.J. and Winch, Raymond (edited by). British Empirical Philosophers: Routledge and
Kegan Paul Ltd, 1952
* Cottingham, John (edited by). Descartes: Oxford University Press, 1998
* Descartes, René. Discourse on Method and the Meditations: tr F.E. Sutcliffe, Penguin Books 1968
* Honderich, Ted (edited by). The Oxford Companion to Philosophy: Oxford University Press, 1995
* Schacht, Richard. Classical Modern Philosophers: Routledge and Kegan Paul Ltd, 1984
(footnote continued)
