The Function of Sceptical Arguments within the Advancement of
Knowledge:
Bacon, Gassendi, Hume
ANIK WALDOW
Introduction
Bacon, Gassendi and Hume are names that are commonly taken to represent classic
empiricism, the doctrine which understands sense data to be the basis for factual knowledge
claims. In grouping these names together it seems that the aim of the essay is to describe how
the empiricist concept of knowledge emerged and opposed rationalist theories as exemplified
by Descartes, Spinoza, Malebrache and Leibniz. It is clearly not my aim in this essay to give a
description of the battles that empiricists needed to fight against their rationalist opponents. In
recent years the labels empiricism and rationalism have been scrutinised and found to be
inappropriate as an account towards early-modern philosophical thought. And although
commentators vary in their opinions as to whether the classic scheme be revised or
abandoned, it seems that the general message continues to be ignored, namely that there is
something wrong with the terms empiricism and rationalism. One example can be found in
Russell Hardin’s recent analysis of Hume. He writes: “Hobbes and Hume are proto scientists
who foremost wish to understand the empirical world. They are not empiricists in the manner
of Francis Bacon and Tycho Brahe, collecting a mass of facts and then inferring conclusions
from them. But they solidly ground their theories and explanations in the real world …
Hume’s Newtonian move is to reach conclusions ‘deduced from the phenomena’”1 One could
here wonder what precisely is the advantage of presenting Hume as an empiricist and of
opposing him to Bacon, while joining him with Newton, when all three of them are
understood to extrapolate principles from the results of observable phenomena.
Unfortunately, even those who try to raise critical awareness of the difficulties relating
to the distinction occasionally slip back into detecting a hidden rationalism in empiricist
accounts, and vice versa. Hans Jürgen Engfer traces the origin of ideas in early modern
philosophy and thus remains bound to the conceptual scheme he ventures to criticise.2 Louis
Loeb, Michael Ayers and David Norton all challenge the story of empiricism by revealing
continuities between those traditionally seen as representatives of the rival camp.3 In so doing
it sometimes seems that all we need to do is reorganise the classificatory scheme, but not that
1
Hardin (2007: 3-4), also see pp. 17, 213, 205.
Engfer (1996)
3
Loeb (1981), Norton (1981), Ayers (1998 and 1991, vol. 1: 15)
2
1
it is necessary to let go of the outworn categories as such, categories which obscure rather
than elucidate what drove early-modern thinkers in their interest in the workings of the human
mind.
In the following I will not attempt to regroup the canon of empiricists, but nevertheless
challenge the classificatory scheme. I will try to show that we can understand the concerns of
early-modern thinkers better if we concentrate on their use of sceptical arguments. These
arguments, as I will point out in discussing Bacon, Gassendi and Hume, did not aim at the
relegation of knowledge claims. On the contrary, I will argue that sceptical arguments were
employed in order to replace and improve a useless concept of knowledge that could no
longer keep up with the advancements in science. The particular purpose of these arguments
consisted in demarcating the reach of the human understanding and in showing at which point
the mind engages in delusion and speculation. In other words, sceptical arguments were
employed as a device that prepared the basis for the advancement of knowledge; they
revealed within which boundaries knowledge could be gained. This way of putting things
makes clear that concerns with sceptical arguments did not result from the awareness of a
severe threat that Popkin understands to have emerged with the availability of the writings of
Sextus Empiricus from the mid-sixteenth century onwards.4 The reason for which Bacon,
Gassendi and Hume took issue with scepticism was rather that the advancement of knowledge
called for a re-adjustment of the available conceptual resources. All of them challenged
Scholastic conceptions of formal deduction and syllogistic reasoning. This suggests that those
that we like to see as empiricists did not line up to establish the dogma that experience is the
basis for knowledge claims against the tenet that all knowledge must derive from reason.5
They opposed dogma themselves, namely the dogma of Scholastic traditions which they
deemed to prevent a fruitful scientific practice.
Sceptical Arguments: a clarification
Commonly it is assumed that those who engage in sceptical arguments are sceptics, while the
sceptic is taken to deny the possibility of knowledge. Ancient scepticism seems to express
such an attitude: the Pyrrhonist urges his adversaries to accept that by means of reason one
cannot know the truth. He does so by presenting counter-arguments that establish the contrary
4
Popkin (2003), for a criticism of Popkin see Ayers (2004).
This picture has been drawn by the Neokantians, who presented Kant as the first to offer a critical perspective
on the school debates between empiricists and rationalists. This approach, however, ignores that pre-Kantian
thinkers were themselves engaged in a critical enterprise. They used sceptical arguments to oppose the
dogmatism of the schools. See for instance Fischer (1909: 15-16).
5
2
of that which had been claimed before. Sceptical arguments here have a critical function.
They call us on the alert, rather than dwell on the defectiveness of the human mind. As a
remedy the Pyrrhonist recommends intellectual suspense: one does not venture to assert the
truth of things and contents oneself with the insight into how things appear to be. 6 Academic
sceptics, at least those of the late Academy, take a more radical stance. They do not merely
doubt the possibility of knowledge; they assert that nothing can be known. But although being
certain in this particular point, they do not urge us to withhold assent in general: if assent is
formulated after the careful examination of all available evidence and as long as it is clear that
one claims things only to be probable but not true, one is entitled to judge.
This account is very brief and cannot grasp the different nuances of ancient scepticism.
What is important for our discussion, however, is that Academic scepticism precludes the
possibility of knowledge only if one rejects a probabilistic concept of knowledge. The
Academics openly endorsed assent to that which, after careful consideration and examination,
seemed justified and probable. Hence, if one accepts these results as pieces of knowledge,
Academics appear to hold on to the claim that things can be known. They seem to deny only
that we can have knowledge which surpasses probabilistic claims. On this perspective,
sceptical arguments can be seen to prepare the grounds for an alternative concept of
knowledge, one that takes into account the limitations of the human mind. If so, it turns out
that sceptical arguments are an option not only for sceptics, that is for those who deny that
something can be known. They are also an option for those who hold on to the belief that
knowledge is possible, because they only point out that the traditional criteria of knowledge
need to be replaced.7 So, it is no contradiction to claim that someone uses sceptical arguments
and yet believes in the possibility of knowledge.8 In the following I will show that Bacon,
Gassendi and Hume employed sceptical arguments in this particular way. They did not want
to deny the possibility of knowledge per se, but only a certain kind of knowledge. The
motivation behind this was that they took themselves to be the advocates of a modern
scientific practice that required new routes to the generation of knowledge.
Bacon: Cures for the Mind
6
This attitude does not necessarily preclude beliefs and opinions that impose themselves on the mind when
something is evident, see Frede (1984). Only theoretical beliefs that result from argument are taken to be worth
opposing. For different interpretations see Burnyeat (1989) and Striker (2001).
7
Or as Elaine Limbrick puts it: “The Academic sceptics advocated a system of methodological doubts which
would free the human mind from the fetters of the past and enable the sceptical enquirer to re-establish
knowledge on a firmer basis.” Limbrick, Introduction in Sanchez (1988: 88).
8
Perler raises this point with respect to medieval sceptical debates. See Perler (2006).
3
Let us first turn to Bacon. Bacon is well aware of the shortcomings of the human
understanding, and in this sense critical and even sceptical because he questions the mind’s
ability to know. The mind, as he tells us in the New Organon and The Advancement of
Learning, is infested by a variety of idols: the idols of the tribe, the idols of the cave, the idols
of the marketplace and the idols of the theatre. The mind must therefore be viewed as an
“enchanted glass”9 or “uneven mirror”10 that “alters the rays of things from their proper shape
and figure, so also the mind, when it is affected by things through the senses, does not
faithfully preserve them, but inserts and mingles its own nature with the nature of the things
as it forms and devices its own notions.”11 This leads him to conclude that “the assertation
that the human senses are the measure of things is false; to the contrary, all perceptions, both
of the senses and the mind, are relative to man, not the universe.”12 This clearly expresses a
certain scepticism: Bacon questions not only that the senses can give a true account of how
things stand; he extends his doubts from the senses to the mind’s general natural powers and
denies that they are sufficient for arriving at a correction of sensory delusions. He thus seems
to line up with the ancient sceptics and their claim that the only things of which we can be
certain are appearances: for the mind projects rather than detects.
Scepticism conceived along these lines can be defined as a position that results from
the awareness of the fiction-enhancing shortcomings of the human mind. Although Bacon
acknowledges the defectiveness of the human mind, he leaves no doubt about the untenability
of the Pyrrhonean suspension of judgement: “In its initial position our ways agree to some
extent with the method of the supporters of the lack of conviction; but in the end our ways are
far apart and strongly opposed. They assert simply that nothing can be known; but we say
simply that not much can be known by the way which is now in use. They thereupon proceed
to destroy the authority of sense and intellect, but we devise and provide assistance to
them.”13 This clearly shows that, instead of giving up on the possibility of knowledge, Bacon
reaches for assistance. Experiments, he explains, can act as a guide to correct judgement.
They aid the senses to take notice “of things that cannot be seen”14, focus and instruct the
mind. Experiments thus provide a sort of straightjacket to the mind: they discipline the
“influence of the will and emotions”15 and reduce the mind’s tendency to spread itself upon
the world. Furthermore, for Bacon the authority of judgement does not lie with the mind; it is
9
Bacon (1950: 133-134)
Bacon (2000: 19)
11
Ibid.
12
Bacon (2000: 41)
13
Bacon (2000: 40)
14
Bacon (2000: 45)
15
Bacon (2000: 44)
10
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the experiment that enables us to know about the nature of things: “Sense only gives
judgement on the experiment, while the experiment gives a judgement on nature and the thing
itself.”16
Certainly, this leaves unexplained how it can be granted that the senses are veridical in
their reports of experiments. Hence, the problem of the deceitfulness of the senses has only
been shifted but not solved. Bacon does not seem to be troubled by this. He claims that the
Academic sceptics were plainly wrong in charging the deceit upon the senses, because they
are “very sufficient to certify and report truth”17 … “perhaps not immediately”18, but with the
aid of reason, experiment and invention. This clearly marks Bacon’s attitude as non-sceptical.
Although he admits that the mind is defective and unable, if unaided, to achieve true
judgement, he is certain that with the assistance of experiments the ignorant state of mind can
be overcome. This reveals that one function of Bacon’s sceptical arguments consists in
identifying the sources of error and delusion which, once identified, can be blocked by the
adoption of experimental methods. Sceptical arguments can thus be seen to contribute to what
Bacon considers as a cure for the disease infected mind: “As in medicining of the body, it is in
order first to know the divers complexions and constitutions; secondly, the diseases, and
lastly, the cures: so in medicining of the mind, after knowledge of the diverse characters of
men’s natures, it followeth, in order, to know the diseases and infirmities of the mind, which
are no other than the perturbations and distempers of the affections.”19
If we revise the nature of the four categories of idols, a further function of Bacon’s
sceptical arguments can be singled out. The idols of the tribe are common to mankind and
derive from the mind’s tendency to assume more order and regularity in nature than there
really is. The idols of the cave relate to each person’s individual inclinations which have been
fostered by education, social surroundings, and the respect for authorities. The idols of the
marketplace are illusions caused by words which are “a poor and unskilful code that obstruct
the understanding”20. The forth group, the idols of the theatre, result from dogma in
philosophy. At first sight, it seems that the first category of idols is concerned with the natural
deficiencies of the mind, while the last three describe delusions which result, at least to a
certain degree, from social influences exerted on an individual’s mind. It is interesting to note,
however, that also the socially steered idols stand in close connection to the natural, illusion-
16
Ibid.
Bacon (1950: 126)
18
Ibid.
19
Bacon (1950: 171)
20
Bacon (2000: 42)
17
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enhancing dispositions of the mind.21 Bacon states that the mind naturally tends to generalise:
“The human understanding from its own peculiar nature willingly supposes a greater order
and regularity in things than it finds.”22 Furthermore, he maintains that “the human
understanding is most affected by things that have the ability to enter the mind all at once and
suddenly, and to fill and expand the imagination.”23 Now it is these two propensities, the
propensity for generalisation and imagination-stimulating events, that are crucially at work
when indulging in the socially steered idols. Bacon explains that idols of the cave are often the
product of “admiration for antiquity”24 or “the love and embrace of novelty”25. In other
words, they are caused by that which calls on our affections and stimulates the imagination.
Idols of the marketplace emerge with distorted meanings which result from a practice that
fails to “reflect particular instances and their sequence and order”26. They are thus affected by
the minds natural propensity to view generalities where one needs to respect uniqueness and
disparities. A similar analysis applies to the idols of the theatre. Bacon writes: “They are
openly introduced and accepted on the basis of fairytale theories and mistaken rules of
proof.”27 He here criticises first Aristotelian syllogistic proof, secondly, the scientific practice
of the “empirical brand of philosophy”28, conceived as the branch of science which derives
rules from an insufficiently large experimental basis, and, thirdly, superstition resulting from
the introduction of “abstract forms and final causes and first causes, and the frequent omission
of intermediate causes”29. The idols of the theatre can thus be seen to be particularly
susceptible to the mind’s natural propensity to generalise too hastily and to ignore individual
instances while dashing ahead to the most abstract principles.
Having shown the dependency of the intersubjectively steered idols on the natural
dispositions of the mind, it now becomes clear that Bacon’s analysis of the shortcomings of
the human understanding is more than a well-meant piece of advice on how to secure the
possibility of knowledge. If, by relying on experiment and method, we succeed in curing the
natural diseases of the mind, we are able to block our natural inclination for idols: not only for
the idols of the tribe, but all Baconian idols because each single one of them takes recourse to
21
Stephen Gaukroger admits that there is an interconnectedness between understanding the preconceptions of the
mind and our knowledge in what direction we need to lead the mind’s thinking. But still he insists that there is a
“significant difference between the Idols of the Tribe and Idols of the Cave”. The latter can be cured by the
method of eliminative induction, the first cannot. See Gaukroger (2003: 637-39 and 2001: 118-131).
22
Bacon (2000: 42)
23
Bacon (2000: 43)
24
Bacon (2000: 47)
25
Ibid.
26
Bacon (2000: 48)
27
Bacon (2000: 49)
28
Bacon (2000: 52)
29
Bacon (2000: 53)
6
undue generalisation, imagination and affection-stimulating elements. Bacon’s discussion of
the limitedness of the mind thus provides a justificatory basis for his attack on dogma and
established conceptions of proof and knowledge. He reveals the need to undercut the mind’s
natural propensity for fanciful theories and, thereby, require us to accept his method as the
cure the advancement of knowledge requires. Hence, for Bacon sceptical arguments have a
strategic aim. This aim consists in criticising the established concept of knowledge and
replacing it with a concept which is more adequate. It is more adequate because it results from
the careful investigation of the human understanding and an awareness of its deficiencies.
Gassendi: Approaching Truth
Gassendi is another example of someone who pays attention to sceptical arguments not
because he is troubled that nothing can be known but because he wishes to raise awareness for
the uselessness of traditional conceptions of knowledge and proof. In his objections to
Descartes’ Meditations he takes a realist stance and points out that Descartes’ doubts are “an
elaborate pretence of deception”.30 Gassendi may accept with the ancient sceptics that
perception is deceptive and that the senses provide us only with appearances. This, however,
does not lead him to conclude that we do not know whether we really perceive or only dream
that we see things with our eyes. When being awake, we know that we are not dreaming. 31 In
the Syntagma he repeats this point. Concerning the question of whether we can know that
things exist beyond the realm of appearances, he maintains: “It is still true and certain that
something exists …Obviously if nothing existed, it would not occur to his [the sceptics] mind
to deny that something exists; and unless he himself were something, he would not reason
along those lines.”32 Gassendi thus tries to lead the sceptic ad absurdum: doubts can only be
formulated, if there is someone existing who is able to formulate these doubts.
In Book II of the Syntagma Gassendi presents himself as someone who follows the via
media between scepticism and dogmatism. On the one hand, he openly supports a
correspondence theory of truth: “The truth which is in the judgement or statement depends
upon the one that is in the thing itself to which the judgement or statement corresponds ... To
inquire after the truth of a thing is nothing but to investigate whether it is, or exists, and what
sort of thing it is.”33 On the other hand, he denies that we have reason to infer that the content
30
Gassendi (2005: 180)
Ibid.
32
Gassendi (1972: 328)
33
Gassendi (1972: 288)
31
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of an idea must exist in the way displayed by the idea. This leaves us with the situation that, in
principle, we cannot know, only conjecture, that our ideas are true, because we cannot know
whether they correspond to the things they purport to display. Gassendi advances this point
against Descartes and his claim that the objective reality of an idea can only have as much
reality as the formal reality of its cause: “An architect makes up the idea of a house in his
mind, and this idea actually consists of the specified walls, floors, roof, windows and so on;
but the house itself and its components do not yet exist in actuality but only in potentiality.”34
His positive views on the possibility of knowledge have often been taken to derive from his
theory of signs. According to this theory, neither the sense nor the intellect is the criterion of
truth;35 both work together when deciphering the sensible signs of the properties of things:
“The indicative sign pertains to things naturally hidden … it is of such a nature that it could
not exist unless the thing exists, and therefore whenever it exists, also the thing exists … An
illustration of this is sweat as it indicates the existence of pores in the skin, for pores cannot be
seen; still sweat is of such a nature that it could not appear upon the skin unless pores existed
through which it could pass from inside to the outside.”36
How does the reading of signs work? Gassendi tells us that the intellect is to judge the
various appearances provided by the senses: “Since experience establishes, and reasoning
based on experience confirms, that objects when distant appear smaller than they are when
they are near to us, the idea of the sun which comes to us through sense-perception is so
amplified by the minds own power as to correspond exactly with the agreed distance of the
sun from us, so that its diameter equals so many radii of the earth.”37 This explains why
Gassendi has no problem with the deceitfulness of the senses: the senses provide appearances,
but appearances are neither true nor false, they need to be assessed by reason in order to gain
an epistemic status.38 The intellect, as the example of the pores suggests, is able to assess the
existence and properties of the unperceived causes. It concludes that certain things, such as
pores, exist because the observable phenomena, such as the occurrence of sweat, require their
existence. Hence, Gassendi is not only a realist about the existence of unperceivable causes,
he is also positive that we can know the properties of these causes, although our senses only
acquaint us with appearances. We can know these properties because the mind is able to
decipher these appearances correctly.
34
Gassendi (2005: 208)
Note that Gassendi discusses this point against the background of ancient scepticism; he is concerned with the
question whether there is a criterion of truth but not with the question of whether the senses are a better
instrument than reason.
36
Gassendi (1972: 332)
37
Gassendi (2005: 198)
38
“It is not the senses but the intellect that makes the error”. Gassendi (1972: 345)
35
8
One could now wonder in which respect Gassendi remains true to his announced
middle way. Does he not subscribe to a theory which asserts that we can know the properties
of things? So what is the sceptical element that is to counter-balance dogmatism? And why
does he admit that “the occasion arises only too frequently in physical science to declare that
we are fortunate if we attain not what is true but what is probable” 39? An answer to these
questions can be provided if we take into account that although Gassendi maintains that in
principle the intellect is able to judge correctly, it often fails in so doing. The reason for this is
not that the will reaches further than the intellect, as Descartes suggests, 40 but because the
mind tends to judge things which have not been observed carefully: “Thus you will be said to
have a perfect idea of a man if you have looked at him carefully and often from all sides; but
your idea will be imperfect if you have merely seen him in passing and on one occasion and
on one side.”41 This suggests as a general rule that the chances to come to hold a correct idea
of something increase with the time and effort we spend on the observation of the thing in
question. Or to put it in sceptical terms: although by sense perception the mind cannot reach
the properties of a given thing straightforwardly, it can nevertheless grasp these properties
indirectly if it relies on a sufficiently large stock of its appearances. The possibility of error
here arises with our uncertainty or ignorance about the point at which a sufficiently large
number of appearances have been gathered. This reveals that for Gassendi knowledge comes
in degrees. The more diligently we study the thing we wish to judge, the better our idea of it.
Surely this understanding of knowledge leaves room for correction. In principle, every new
examination can reveal aspects we have not considered before and this can urge us to revise
our previously formed idea. This is why Gassendi concludes: “We do not have the power so
much as to guard against error as to guard against persisting error”42
All in all it thus seems that Gassendi’s via media leads to a concept of knowledge that
allows us to formulate tentative, probabilistic judgement that can be refuted by further
evidence.43 Knowledge here presents itself as a matter of approaching truth. For the time
being and according to our previous observations we regard a thing as “truer than its opposite,
irrespective of whether it really accords with the truth of the matter or not.”44 This seems to be
reminiscent of Academic scepticism. One does not claim to know the truth but merely that the
available evidence indicates the probability of one’s claims. Admittedly, Gassendi often
39
Ibid.
Descartes (2005: 37-43)
41
Gassendi (2005: 199)
42
Gassendi (2005: 220)
43
Hence probabilistic knowledge can be characterised by having an opinion (as opposed to knowing) that
something is true, rather than by believing in the probability of appearances. See Hacking (1971: 21-22).
44
Ibid.
40
9
sounds less careful. For instance, he speaks of the possibility to have a perfect idea of a man.
But how can something perfect be improved by further examination? And how can a perfect
idea not be taken to indicate the truth? To answer these questions it needs to be considered
that Gassendi distinguishes between appearances and the things in re and opposes this pair of
categories to the traditional distinction between accidents and substance: “I claim that we do
have a distinct and genuine idea of accidents, but that our idea of the unseen substance
beneath them is confused and utterly fictitious.”45 Against this background it emerges that the
idea of a man is perfect in as much as it is based on the appearances of his perceivable
properties, that is on accidents displayed by the senses. On the contrary, this idea would
remain obscure if it were based on something which is not perceivable, something
unperceivable like a substance: “If you have not seen the man himself but only a mask
covering his face and a set of clothes which completely cover his body, then we must say that
either you do not have an idea of him at all or, if you do have one, that it is very imperfect and
utterly confused.”46 Hence, an idea is perfectly formed if it is based on the perceivable
accidents of the thing in question; it need not reflect a grasp of its unperceivable substance.
This suggests that Gassendi advocates a concept of knowledge that stays with the
phenomena. He thus holds on to a concept which he already defended in the “Exercises
against the Aristotelians”.47 In Book II he argues against the Aristotelian requirement that
knowledge be obtained through an acquaintance with causes conceived as the nature, form or
essence of the things perceived.48 Gassendi remarks critically that “the inquiry after causes
follows upon the observation of effects”49. So he asks: “Aren’t effects better known than
causes?”50 This clearly urges us to accept that knowledge needs to be based on that which we
can perceive and study. It is the better kind of knowledge because it is less speculative: it
allows for an inference to the external properties of things but does not pretend to reveal their
nature or essence. This clearly goes against dogmatism standing in the tradition of Aristotle.
Gassendi writes: “Yes, Aristotle, dear Peripatetic! Yes indeed the fundamental elements of
reality are matter, form and privation. All I ask is that, using these, you explain to me the
45
Gassendi (2005: 199)
Ibid.
47
Howard Jones sees Gassendi’s discussion of signs to be consonant with his account of knowledge as provided
in the Carpentras Logics. Howard, however, fails to see that this theory also conforms with Gassendi’s early
attacks on Aristotelianism. See Gassendi, Introduction (1981: XLVIII). On the contrary, Margaret Osler (1994:
102-103) points out against René Bloch who calls the Syntagma »an assamblage of historical, scientific, and
philosophical discussions” Bloch (1971: 3) that the continuity of Gassendi’s thoughts is obvious.
48
Gassendi (1972 : 86)
49
Gassendi (1972 : 84)
50
Ibid.
46
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essence of just one single thing.”51 His point is that if we had knowledge of these fundamental
elements of reality, we would know the essence of things and could dispense with further
investigations as conducted in science. However, it is apparently not the case that we have
such knowledge, otherwise we could explain things as simple as the question of what makes a
flea bite other creatures. Gassendi’s appeal for a concept of knowledge based on the study of
the phenomena thus turns out to be an appeal for a concept that reflects the limitedness of the
human mind. He urges us to study our perceivable surroundings, because this is the only way
we can achieve insight into how the world is organised.
This short outline of Gassendi’s treatment of perception as the basis for knowledge
reveals that he uses sceptical arguments as a foil against which he advances his own cognitive
theory: the senses and the intellect, if taken together, can inform us about the properties of
things. Sceptical arguments thus provide a means that allow him to establish not only a
weaker concept, but a concept of knowledge which reflects a modern scientific practice and
dispenses with demonstration and syllogism and the categories of essence and form. It
appropriates that knowledge can turn out to be false, precisely because it is not the essence of
things which can be grasped. This alternative concept nevertheless qualifies as genuine. It is
better than its Aristotelian rival, because it binds knowledge claims to the realm of the
perceivable; it can thus be expected to limit speculations to a minimum. Similar to Bacon, this
move towards a new concept of knowledge is made by the analysis of the abilities of the
human mind. Gassendi claims that the human mind is incapable of grasping essences,
therefore it needs to reach for something else.
Hume: Appeal to Human Nature
Hume follows a similar path when taking issue with ancient sceptical arguments. As we have
seen, one of Gassendie’s strategies in dealing with the sceptic is to challenge him on his own
grounds by urging him to accept that he cannot consistently doubt the existence of things
without accepting that he exists himself; and this serves him as the basis for his theory of
signs, which claims sensations to indicate real existences. At first sight, Hume seems to
provide a similar answer to the sceptic by appealing to nature as a block to artificial and
exaggerated doubts: “Nature, by an absolute and uncontroulable necessity has determin’d us
to judge as well as to breathe and feel”52. This seems to oppose Pyrrhonism, at least as it is
presented by Hume, for he takes it to be an illusion in itself that one can suspend judgement.
51
52
Gassendi (1972: 97)
Hume (1978: 183)
11
In other words, Hume claims that no one, not even the Pyrrhonist, can doubt: nature forces us
to assent and thus to have opinions and beliefs.
Pyrrhonims has often been understood to allow for opinions and beliefs, in so far as
these beliefs are held in the common course of life.53 Whether or not one takes Hume here to
identify with Pyrrhonism thus depends on whether one is ready to see Pyrrhonism as a
position which allows for opinions in everyday life. It is clear from the outset, however, that if
Hume agreed with Pyrrhonism it would be difficult to argue that sceptical arguments served
him as a means to replace the established conception of knowledge by a more scientific one.
Pyrrhoists may allow for opinions, but these opinions are not seen to result from critical
examination; they are taken to impose themselves without the need for any reflection. 54 So it
seems that Pyrrhonists can concede that belief may be unavoidable, but this does not give
belief a rational basis. Hume can certainly be read in a similar vein. Although he admits that
in everyday life nature urges us to assent, Hume does not see reflection as a precondition for
natural belief. On the contrary, reflection would destroy rather than endorse belief: “Let our
first belief be never so strong, it must infallibly perish by passing thro’ so many new
examinations, of which each diminishes somewhat of its force and vigour.”55 This presents
Hume’s appeal to nature as undermining rather than supporting the claim that we can have
knowledge of whatever weak kind. This is because knowledge certainly requires more that the
mere psychological urge to assent. Hence, it looks as if Hume’s answer to the sceptic is no
answer at all. He seems to agree with the Pyrrhonists that we can merely believe, but not
know.
If one wishes to understand Hume as a thinker who abandoned the idea of knowledge,
one should stop at this point and conclude that, for Hume, there is nothing more to belief than
our psychology. Hume, however, does not finish with these words. In the final chapter of
Book I he goes through dramatic stages which present him to be torn between the awareness
that “we have… no choice left but betwixt a false reason and none at all”56 and the pragmatic
attitude that “I find myself absolutely and necessarily determin’d to live, and talk, and act like
other people in the common affairs of life”57. He almost seems convinced that it is best to
throw his books into the fire and to give up on philosophy altogether, when finally the turn
comes. In the midst of his doubts Hume feels an ambition arising within him to contribute “to
53
Baxter argues that Hume was closer to the Pyrrhonims as presented by Sextus Empiricus than the Pyrrhonism
presented by himself. See Baxter (2008: 8).
54
For the discussion of this question see Frede (1984).
55
Hume (1978: 182-183)
56
Hume (1978: 268)
57
Hume (1978: 269)
12
the instruction of mankind”58 and to acquire a name by his inventions and discoveries. He
declares: “These sentiments spring up naturally in my present disposition; and shou’d I
endeavour to banish them, to any other business or diversion, I feel I should be a loser in point
of pleasure; and this is the origin of my philosophy.”59 Two points are remarkable about this
passage. First, it clearly reveals that Hume holds it possible that he can contribute to the
instruction of mankind. This entails that he takes himself to be able to find out something
which is relevant enough to be taught to others, something which is important and useful for
others to know.60 Secondly, the passage suggests that the means by which he expects himself
to be able to generate such useful insight is philosophy. Note that Hume often refers to
philosophy as an activity of reason that leads to a belief system that is opposed to the system
of the vulgar which consists of the natural beliefs of our everyday lives.61 In suggesting
philosophy to be the activity by which the instruction of mankind can be realised, Hume
therefore exhibits the belief that reasoning is an activity worthwhile pursuing and that it can
serve as an instrument which enables us to emancipate ourselves from the grip of nature.
This positive spirit seems bizarre. Hume admitted just before that belief is caused by a
feeling and that “memory, senses, and understanding, are, therefore, all of them founded on
the imagination”62. And this is precisely the reason for which he sought relief at the
backgammon table, conversed and was merry with his friends and abandoned any intellectual
activity. To explain this it needs to be recognised that even after the above mentioned turn
Hume continues to view feelings as an indispensable ingredient in the activity of reason.
Hence, despite his positive attitude, he remains consonant with his earlier conclusion, namely
that assent is caused by “nothing but a strong propensity to consider objects strongly in that
view, under which they appear.”63 What seems to have changed, however, is his attitude
towards this propensity or feeling. It seems that feelings and propensities are not only no
longer seen as an impediment to reason; stronger than that, it seems that reason and
philosophy are even legitimised by them.64 This becomes clear when considering that Hume
talks about philosophy as just. Just philosophy is described as an intellectual activity which
58
Hume (1978: 271)
Ibid.
60
We also find this requirement that knowledge be useful and instructive in Bacon. See Gaukroger (2006: 196207 and 2001: 150-159).
61
Philosophy, Hume tells us, generates its opinions by the use of reason, while the “conclusions, which the
vulgar form on this head, are directly contrary to those, which are confirm’d by philosophy.” Hume (1978: 193)
62
Hume (1972: 265)
63
Ibid.
64
This point has been made most prominent by Garrett (1997: 178 and 2006: 196) who ascribes to Hume the socalled ‘title-principle’ according to which Hume wants us to assent only “where reason is lively and mixes itself
with some propensity … Where it does not, it never can have any title to operate upon us.” Hume (1978, 270)
59
13
“can present us with mild and moderate sentiments”65 and is contrasted with “false and
extravagant”66 reasoning which leads to “cold and general speculation, and seldom go[es] so
far as to interrupt the course of our natural propensities”67. The message of this is that reason
needs to integrate our natural propensities and feelings.68 Only then can it have an influence
on us and oppose that sort of superstition which “arises naturally and easily from the popular
opinions of mankind, and is often able to disturb us in the conduct of our lives and actions”69.
Hume’s legitimatory strategy thus turns out to consist in, first, specifying the purpose of a
satisfactory philosophy, that is to provide protection against superstition and speculation in
our everyday lives, and, then, by indicating how this can be achieved, namely by integrating
our natural belief directing propensities into philosophical reasoning. Slightly differently put,
Hume is aware of the fact that feelings cannot be subtracted from belief-forming processes.
This circumstance, however, is not conceived of as a flaw that justifies the sceptic in his
doubts. On the contrary, the share in our natural propensities is taken to mark that kind of
reasoning which is able to block superstition and speculation. Reasoning is able to do so if it
connects to our sentient nature, because only then does it have an impact on how we conceive
of the world.
If reasoning is carried out along these lines, Hume is convinced that the advancement
of knowledge is possible: “For my part, my only hope is that I may contribute a little to the
advancement of knowledge, by giving in some peculiars a different turn to the speculations of
philosophers, and pointing out to them more distinctly those subjects, where alone they can
expect assurance and conviction”70. One may here ask what kind of knowledge is it that
Hume envisages on the last pages of Book I? Hume speaks of assurance and conviction. A
few lines before he says that philosophy is to provide “steady principles”71 which will “suit
with common practice and experiment”72 and that it is to avoid “hypotheses embrac’d merely
for being specious and agreeable”73. Rather modestly he then concludes: “Were these
hypotheses once remov’d, we might hope to establish a system or set of opinions, which if not
true (for that, perhaps, is too much to be hop’d for), might at least be satisfactory to the human
mind, and might stand the test of the most critical examination.”74 If taken together this
65
Hume (1978: 272)
Ibid.
67
Ibid.
68
Kail (2007: 66-69)
69
Hume (1978: 271)
70
Hume (1978: 273)
71
Hume (1978: 272)
72
Ibid.
73
Ibid.
74
Ibid.
66
14
suggests that knowledge need not be known to be true; it is sufficient if knowledge suits our
common practices, if it provides us with principles extracted from experiments gleaned up
“from a cautious observation of human life”75. Furthermore, the kind of knowledge that Hume
views as worthwhile to be advanced is of the sort that dispenses with broad generalisations.
Hume writes: “We shou’d yield to our propensity, which inclines us to be positive and certain
in particular points, according to the light, in which we survey them in any particular
instance”76. Hence, the concept of knowledge that emerges as the result of Hume’s sceptical
arguments is based on careful examination. It may not aspire to display the truth of things, but
it enables us to explain observable phenomena by providing us with principles to which the
phenomena seem to respond.
This presents Hume to stand closer to Academic scepticism than Pyrrhonism. After all,
Hume advocates assent after the careful consideration of things; hence, it is not merely nature
which urges us to believe: we judge upon a rational standard because we systematise and
evaluate the previously observed phenomena. Furthermore, it needs to be recognised that
Hume holds the advancement of knowledge to be a realistic enterprise. Similar to the
Academics, he can thus be seen to subscribe to the doctrine of nihil scitur only if it is taken
for granted that he holds on to the conception of knowledge as something which is infallible
and certain. If he is understood to opt for a new, probabilistic concept of knowledge, he is no
sceptic at all. His fascination with the progress in the sciences and his wish to contribute to
the advancement of knowledge strongly endorse the second interpretation. Sceptical
arguments thus turn out to possess the already outlined function. They show what the mind
can achieve and, on this basis, prepare the grounds for a concept of knowledge that
undermines the realm of speculation by confining investigations to that which lies within the
reach of the human mind.
Conclusion
Bacon, Gassendi and Hume are thinkers who all seem to have in common that they enter into
the sceptical debate in order to reveal the need for a new concept of knowledge. That is a
concept that is able to keep up with the advancements in science. Thus, Bacon and Hume both
are especially interested in promoting knowledge which is useful, that bears importance in our
everyday lives and is not subject to endless school debates. Gassendi seems to pursue a
similar aim when claiming that Aristotelian knowledge that consists in the grasp of essences
75
76
Hume (1978: xix)
Hume (1978: 273)
15
and forms plainly does not exist. All of them put particular emphasis on the relevance of
observable phenomena. The reason for this is not that they wish to diminish the importance of
reason. Rather they wish to render knowledge less speculative and amenable for correction.
This shows that Bacon, Gassendi and Hume employ sceptical arguments not because
they are troubled by a crisis or for fear that nothing can be known. All of them reject the
suspension of judgement and hold on to the belief that knowledge is possible. It is possible if
we understand and respect the limits of the human mind and adjust our methods of knowledge
generation to the status quo. Sceptical arguments thus turn out to illuminate what the mind
can achieve; they thereby clear the grounds for the development of a realistic concept of
knowledge. This presents the function of sceptical arguments to consist not so much in the
weakening of the existing concept, which would amount to a defeat. Rather it consists in the
replacement of a deficient, speculation enhancing concept by a better one. If one focuses
merely on what is empiricist in Bacon, Gassendi and Hume’s concept of knowledge as
opposed to rationalist conceptions this particular use of sceptical arguments will certainly be
ignored. It then seems that these arguments aimed at the refutation of doubts - doubts the
empiricist wants to neutralise by empirical methods, while the rationalist opts for analytical
reasoning – although the aim of invoking sceptical arguments was clearly not the refutation of
doubts but the replacement of dogmatic and useless conceptions of knowledge.
University of Sydney
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