CARTESIAN RATIONALISM VERSUS LOCKEAN EMPIRICISM.
A CONSIDERATION OF CARTESIAN RATIONALISM.
Descartes' scepticism concerned the validity
of accepted ideas. He believed that knowledge
is acquired by reason without resort to experience.
Because of the dangerous religious Zeitgeist
his response was necessarily careful and
accommodating.
For epistemology in general
and Descartes in particular the critical
enquiry is how do we know what we know? Is
knowledge innate - or does humanity have
a congenital ability to receive sensory information
experientially as Locke later believed? His
sceptical response was the most comprehensive
and scrupulous epistemic overhaul, re-examination
and regeneration of western philosophical
ideas ever to be undertaken. His resulting
system was rationalist and foundational.
It was grounded in the hierarchically conceived
belief in the idea of God, and from thence
to reason and the senses.
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'All that I have, up to this moment, accepted
as possessed of the highest truth and certainty,
I received either from or through the senses.
I observed, however, that these sometimes
misled us; and it is the part of prudence
not to place absolute confidence in that
by which we have even once been deceived.'
(Descartes. 1.3)
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Beginning with
a questioning of his own existence his work
is mainly concerned with a conscientious
journey of enquiry into his own mind, God
and the physical world itself. He painstakingly
considers the possibility that everything
which our senses provide to enable our access
to the external world and the intrinsic domain
of the soma is suspect. He conjectures that
the external world instantiated by the senses
could be no more than a dream and not exist
at all.
However we do find one strange
anomaly in his analysis:
'At the present moment, however, I certainly
look upon this paper with eyes wide awake;
the head which I now move is not asleep;
I extend this hand consciously and with express
purpose, and I perceive it; the occurrences
in sleep are not so distinct as all this.
' (Descartes. 1.5)
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We can be forgiven for enquiring
how he can be so sure, for this Lockean-style
acceptance of the veracity of the senses
obviously conflicts with what he says in
the next sentence:
'But I cannot forget that, at other times
I have been deceived in sleep by similar
illusions; and, attentively considering those
cases, I perceive so clearly that there exist
no certain marks by which the state of waking
can ever be distinguished from sleep, that
I feel greatly astonished; and in amazement
I almost persuade myself that I am now dreaming.'
[Descartes. l. 5]
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How is he so 'certain' that
this is not one of those 'other times?' Why,
shortly after saying that the state of waking
can ever be distinguished from sleep does
he accept the testimony of his senses as
evidence that he is not asleep. Why the sudden
certainty of his wakefulness and reliance
upon the sense-derived empirical evidence
that his eyes are open and his head appears
to move?
But what of his demon? The
hypothetical existence of a malicious demon
who sabotages our cognitive faculties is
an impressive philosophical and literary
device or epistemological instrument for
challenging and derailing our belief in our
powers of reasoning and the quality of our
sensory effectualness. It is a brilliantly
conceived conceit which Descartes cleverly
rejects with the simple expedient of professing:
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'Doubtless, then, I exist, since I am deceived;
and, let him deceive me as he may, he can
never bring it about that I am nothing, so
long as I shall be conscious that I am something.'
[Descartes. 11.3]
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Moving on to consider the persuasiveness
of his concept of the self, we note that
for Descartes the self is:
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'It is a thing that doubts, understands,
[conceives], affirms, denies, wills, refuses;
that imagines also, and perceives.' [Descartes.
11.8]
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Using reason anything
of the external world which we can perceive
"clearly and distinctly' is believable.
Extrapolating from the distinct ideas instantiated
within this consciously perceiving self,
he takes these innate ideas to prove the
existence of God. Referring to God's properties
he continues:
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'But these properties are so great and excellent,
that the more attentively I consider them
the less I feel persuaded that the idea I
have of them owes its origin to myself alone.
And thus it is absolutely necessary to conclude,
from all that I have before said, that God
exists.' [Descartes. III. 22]
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Was his conclusion that God
exists really derived from the fact of his
Jesuitical education? The Jesuit watchword
is: "Give me the child and I will give you
the man." At the age of ten the young Descartes attended
the Jesuit College of La Fleche, where the
child remained for eight years.
Whatever the origin of his
construct, his discovery that he could be
sure of the content of his own thought and
the existence of a non-deceiving God [III.
8] freed him from the loneliness of solipsism
and provided him with the encouragement and
unambiguous foundational ontological confirmation
he sought. The sempiternal being, God, really
exists, so the supposed truths of mathematics
and logic etc., are true too, for that they
should be false would be incompatible with
the existence of a non-deceiving god. [Descartes.
5.15.]
In Descartes' ontology 'ideas' are images which represent something. Ideas
are restricted to when we think - for example
of 'a man, a chimera or an angel or God.' He believes in a duality of mind and body.
It is sufficient that he is able to clearly
and distinctly conceive one thing apart from
the other in order to be certain that one
is different from the other. [Descartes.
6.8.]
I will now compare Cartesian
ideas with the empirical beliefs of Locke.
AN EXPLORATION OF LOCKEAN EMPIRICISM.
Much of Locke's work is influenced
by Descartes and is characterised by an opposition
to authoritarianism. The external world and
our perception of it is reliable and:
'The senses serve their purpose
well enough!' [Locke IV. XI, 8]
He feels hunger and other bodily urges and
has no qualms regarding the fact that he
exists.
My sensations - e. g. hunger - give me proof
of my own existence [Locke IV, I,2]
Neither he or anything
else could have come from nothing - so there
must be a creator:
Since I
know I exist, and since it is intuitively
obvious that nothing can come from nothing,
an eternal being must also exist .'[Locke
IV, X, 4.]
Everything we know comes
from the experience of our ideas which come
from the external world. The word 'idea' had a special meaning - toothache is an
idea. But whilst he believed that propositions
could be true or false, he did not believe
that 'true ideas' exist [Locke II. XXXII.
3.]
Innate ideas are rejected
at great length. He insists that there is
a definite difference between dreaming and
reality, and the suggestion that we are disembodied
dreamers is given short shrift and is disregarded
in one dismissive sentence:
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'If our dreamer pleases to try whether the
glowing heat of a glass furnace be barely
a wandering imagination in a drowsy man's
fancy, by putting his hand into it, he may
perhaps be wakened to a certainty greater
than he could wish...[Locke IV. XI, 8]
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It is qualities which cause
us to have ideas and sensations and these
causal qualities are separated into primary
and secondary versions which are subdivided
into primary ones like solidity, extension,
figure, and motion etc.,
which are real and the ideas of them are
resemblances of them. Secondary qualities
produce 'impulsive powers' which impart in
us sensations, some of which powers are dispositional
(potential) like fragility. Locke differs
from Galileo for whom the only qualities
were:
| 'That substance as bounded and as possessing
this or that shape, as large or small in
relationship to some other body who called
these effects 'sensations.' [Galileo, pp.
719] |
Lockian-type secondary qualities for did
not exist for Galileo who writes:
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'/ think, therefore, that these tastes, odours,
colours, etc., so far as their objective
existence is concerned, are nothing but mere
names for something which resides exclusively
in our sensitive body (corpo sensitivo),
so that if the perceiving creatures were
removed, all of these qualities would be
annihilated and abolished from existence.
[Galileo, pp. 720]
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Locke was careful to
explain that whilst all secondary qualities
are powers, not all powers are secondary
qualities, but trouble looms for Locke from
Bishop Berkeley who considers Locke's differentiation
between primary and secondary qualities as
unsound, because as Berkeley correctly says,
we can still make assessments and classifications
of secondary qualities. It might therefore
be the case that all qualities are in the
objects, and how could we possibly know that
it is external objects which cause the sensations
within us?
Berkeley offers an substitute
ontological system which suggests that all
objects of knowledge are only instantiated
into existence by the perception of the observer.
Our own sensations are apodictic, so that
all sensible qualities exist only in the
mind of the perceiver, and Locke's notion
that they result from external causality
is just guesswork.
| 'In short, let anyone consider those arguments
which are thought manifestly to prove that
colours and tastes exist only in the mind,
and he shall find they may with equal force
be brought to prove the something of extension,
figure, and motion.' (Berkeley. XV.I) |
CONCLUSION.
Descartes was undoubtedly
a great thinker and has earned his place
in the pantheon of philosophy. As Grayling
[who controversially suggests that Descartes
was a Jesuit spy] points out:
| 'At his birth in 1596 the world was still
dominated by medieval beliefs in phenomena
such as miracles and spontaneous generation.
It was Descartes who identified the intellectual
tools his peers needed to free themselves
from the frozen grip of religious authority,'
[Grayling 2005] |
Descartes' 'foundationalist metaphysics' and theological proof for God's existence,
is in my opinion entirely unpersuasive and
it has been met with much justifiable criticism.
The major flaw both in the entire Cartesian
systemic process is the fact that God is
utilised to guarantee the dependability of
the human perceptive mind, whilst the same
God's existence is demonstrated because of
the certainty of anything which he clearly
and distinctly perceives. This argument depends
on the initial assumptions needed to prove
God's existence in the first place.
(1) I am certain that God exists only because
I am certain of anything I clearly and distinctly
perceive.
(2) I am certain of anything I clearly and
distinctly perceive only because I am certain
that God exists.
This is known as the 'Cartesian circle.'
I would not presume that Descartes was ignorant
of the circle he created. His familiarity
with circular reasoning was not new, for
in his dedicatory letter to the authorities
of the Sacred Faculty of Theology of Paris he confesses:
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'... the same Being who bestows grace to
enable us to believe other things, can likewise
impart of it to enable us to believe his
own existence), nevertheless, this cannot
be submitted to infidels, who would consider
that the reasoning proceeded in a circle.
[Intro. Letter. II. L13]
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I am more persuaded by
Locke when he claims that 'true ideas' do
not exist, and that only propositions can
be logically true or false as in logic. [Locke
IIXXX. 3]
Descartes is right that the
senses cannot always be trusted, for two
objects that project the same visual angle
on the retina can appear to occupy very different
proportions of the visual field if they are
perceived to be at different distances.
However, regarding Descartes' figurative
arrangement of cords and bells to represent
the 'missing limb syndrome' problem, I am more persuaded by the modern
neurological explanation, where the brain
is the source of the sensations.
'When the area of the brain assigned to the
lost limb no longer receives sensory input
from the area, it begins to react to sensory
input arriving at adjoining areas in the
brain. In other words, the idle area overhears
nearby signals that are being processed and
acts upon them in error.' [Ramachandran.
p. 51.] |
To return once again to the crux of the question
of persuasiveness. I find Locke's more commonsensical
approach and pragmatic level-headedness more
satisfying and cogent. It has long been my
belief that there is no Cartesian duality
and my line-by-line scrutiny and extensive
background reading of the ideas contained
in the six Meditations has done nothing to
persuade me otherwise.
For me as an eliminative materialist
most of the abstract variables which occupy
the minds of the protagonists simple do not
exist. In my ontology the human holism [physical
unity] is apprised of its intrinsic and extrinsic
knowledge via the sensors [not senses] and
from thence to the moderating brain. The
brain constantly updates and modifies its
existential modalities, conducted by incoming
contemporaneous data ideationally mediated
by stored and recalled memories of past experiences.
I believe it is upon this physiological fact
backed up by modern neurological science
that our human temporal progression through
life is founded, on a sensorial trial and
error basis - a physiological actuality upon
which contingence and provision all of us
humans and our sciences are dependent.
REFERENCES.
1. Descartes. R. The Meditations. HTML Edition
Edited by David B. Manley and Charles S.
Taylor. http://www.wright.edu/cola/descartes/
last accessed 28.02.2006.
2. Locke. J. (1689) An Essay concerning Human
Understanding, ed. A. D. Woozley, Glasgow:
William Collins,
1964.
3. Grayling, A. C. The Life of Rene Descartes
and Its Place in His Times. Author: A. C.
Grayling Free Press.
2005-10-03 ins fl.
4. Galilei. Galileo. // Saggitore (The Assayer)
1623. Introduction to Contemporary Civilization
in the West. Columbia University Press, 1954),
vol. I, pp. 719-24.]
5. Berkeley. G. A Treatise Concerning the
Principles of Human Knowledge. 1998) Publisher:
Oxford University Press.
6. Ramachandran. V. S. Phantoms In The Brain
(William Morrow, 1998) BACKGROUND READING.
1. Hobbes, Thomas. Leviathan, (London: Dent,
1973 [first pub. 1651]),p. 65. Rachels, The
Elements, p. 51.
2. Peter Winch, 'The Universalisability of
Moral Judgements', The Monist 49 (1965),
p. 212. S. Cottingham, John. The Cambridge
Companion to Descartes 1992. Pitt Building,
Cambridge, pp. 24 - 25 2.
4. Norman, Malcolm. Dreaming and Skepticism.
Philosophical Review, Vol. 65, No. 1 (Jan.,
1956), p. 14
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