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Scientific Realism and Basic Common Sense

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Scientific Realism and Basic Common Sense
Howard Sankey
(School of Historical and Philosophical Studies, University of Melbourne)
[email protected]
For the scientific realist, the aim of science is to arrive at the truth
about the world. Scientific progress consists in progress toward that
aim. The world that science investigates is an objective reality that
exists independently of human cognition. We interact with the world
by means of action, but we do not create it. Nor does the world
depend on human mental activity.
The result of successful scientific inquiry is knowledge. Scientists
discover facts about unobservable entities whose behaviour is
responsible for that of observable entities. They propose theories
which refer to unobservable entities in order to explain observed
phenomena. Empirical evidence provides reason to believe that
theories which refer to unobservable entities are true.
Scientific
knowledge is not restricted to the realm of the observable. It extends
to the underlying nature of reality by identifying unobservable causes
of observed phenomena.
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Scientific Realism and Basic Common Sense
The realist position that I have just sketched reflects an attitude of
epistemic optimism. According to scientific realism, science produces
knowledge of an independently existing world. As science progresses,
it increases the amount of truth that is known about the world. While
allowing that science is fallible, the realist endorses a robustly antisceptical view of science.
But while realism provides an optimistic assessment of scientific
knowledge, an important question remains about the nature of such
knowledge. Is science an extension of common sense, or does the
advance of science lead to the overthrow of common sense by
scientific theory?
To bring the question into focus, I will use a famous example due
to Arthur Eddington. Eddington began his Gifford lectures in the
following terms:
I have settled down to the task of writing these lectures and have drawn
up my chairs to my two tables. Two tables! ... One of them has been
familiar to me from earliest years. It is a commonplace object of that
environment which I call the world ... It has extension; it is
comparatively permanent; it is coloured; above all it is substantial
...Table No. 2 is my scientific table ... My scientific table is mostly
emptiness. Sparsely scattered in that emptiness are numerous electric
charges rushing about with great speed ... There is nothing substantial
about my second table. It is nearly all empty space ... my second
scientific table is the only one which is really there – whatever ‘there’
may be.1
Eddington’s words, the “scientific table is the only one which is
really there”, suggest that the solid table of common sense does not in
fact exist. Only the insubstantial “scientific table” is real. Thus, the
example of Eddington’s table is a case in which science overthrows
1
12
Eddington, 1933, xi-xiv.
Kairos. Journal of Philosophy & Science 10, 2014
Center for the Philosophy of Sciences of Lisbon University
Howard Sankey
common sense. The table of science is real. The table of common
sense is an illusion to be eliminated by science.
Eddington may be right that there is a conflict between the
scientific and the commonsense descriptions of the table. But the
contrast between two tables is misconceived. There is only the one
table that is revealed in ordinary experience. The nature of the table
may be explained by science. Indeed, the scientific explanation of the
solidity of the table may displace the explanation provided by common
sense. But Eddington’s “scientific table” is the very same table as the
table presented by common sense. There is no further scientific table
in addition to the table of common sense.
Unlike Eddington, I wish to preserve common sense. Science goes
beyond common sense, but does not discard it. Rather than overthrow
common sense, science explains it. Common sense provides our
grounding in the world. It is the foundation upon which scientific
realism rests.
But the notion of common sense is ambiguous. I say that science
goes beyond common sense and that common sense provides a
foundation for scientific realism. This may be understood in different
ways depending on how common sense is understood. To avoid
misunderstanding, I will now seek to clarify the notion, starting with
what I do not take common sense to be.
Common
sense is
sometimes
taken to be practical
skill.
Tradesmen and technicians have different practical skills. But common
sense is more basic than any specific practical skill. It is shared by
those who possess different practical skills. Indeed, it is shared by
those who lack practical skills.
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Scientific Realism and Basic Common Sense
Common sense is sometimes identified with beliefs that are
widely held within a culture. No doubt, commonsense beliefs are
widely held within a culture. But there are many widely held beliefs
that are not commonsense. Throughout history, people have been
committed to a variety of beliefs that defy common sense. So common
sense cannot be the same thing as widely held belief.
By contrast with practical skill and widely held belief, I wish to
focus on a more basic form of common sense. David Armstrong
speaks of “bedrock common sense”.2 Alan Musgrave has suggested to
me that the expression “instinctive belief” may be more appropriate
than ‘common sense’. Whatever form of words we adopt, I wish to
speak of a basic form of common sense that is distinct from practical
skill and widely held belief. I will call it “basic common sense”, though
I shall often just say “common sense”.
The idea of common sense trades on two different meanings of
the word ‘sense’. We can use the word ‘sense’ to speak about the
sensory modalities, such as sight, hearing or smell. But equally it may
be used to signify sound practical judgement, as in having good
sense.
Common sense is typified by our unreflective awareness of the
world around us, and by the routine way in which we deal with objects
in our immediate vicinity. Observation and knowledge derived from
observation play a central role in common sense. But common sense
goes beyond mere observation. It is common sense to believe that
ordinary objects do not disappear while we are asleep and reappear
2
14
Armstrong, 2004, 27.
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just as we awake, though this is not something that we could observe
to be the case.3
Realism about the everyday world is part and parcel of common
sense. The world of common sense is a world of material objects of all
shapes and sizes, with a multitude of properties. We acquire more or
less immediate knowledge of such things by means of our sensory
experience of those objects.4 The material objects that we encounter
in everyday experience are independently existing things with which
we interact causally by means of bodily movement and action. But
though we interact with such objects, they lie beyond the control of
our minds. Mere thought alone cannot bring about change in the
world of objects. The commonsense world is also a world in which
misperception and illusion have their place in the ordinary course of
events without giving rise to scepticism. A robust sense of reality
provides us with a reasonable degree of practical certainty that things
are by and large as they appear to us.
Common sense gives rise to a body of beliefs about the objects in
our environment, the nature of our interactions with these objects,
Equally, it is common sense to disregard such sceptical scenarios as being
brains in a vat, or deceived by an evil demon or created ex nihilo five minutes
ago, though we could not show such scenarios to be false by empirical test. In
my view, such commonsense rejection of scepticism about the external world
may be upheld on broadly naturalistic and Moorean grounds. But as my main
concern in this paper is the relation between science and common sense, I will
not pursue the issue of scepticism about the external world in greater detail in
this context.
4
At this point, the question may arise of whether there is anything more to
common sense than belief arrived at on the basis of direct perceptual
experience of objects in our immediate vicinity. In my view, common sense is
more than perceptual belief and is not to be identified with such belief. In
addition to belief derived from experience, common sense involves an
attitudinal component which is manifest in the way we interact with the
ordinary objects in our immediate environment. Common sense is imbued
with a thoroughly realist attitude to the everyday world, and is not restricted
to the dictates of immediate sensory experience. I make this point in response
to a referee who presses for a more positive delineation of what I take to be
involved in basic common sense.
3
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Scientific Realism and Basic Common Sense
and the means by which we may acquire knowledge of such things. On
the whole, we may assume that this body of beliefs is true. This is not
because commonsense beliefs are guaranteed to be true. Like all
beliefs, they are fallible. But they have a strong presumption in their
favour. Common sense has a prior claim on our belief. Beliefs based
on common sense occupy a central place in our belief system. As
such, they are only to be rejected after less pivotal beliefs have been
considered for rejection. Given their privileged status, any challenge to
common sense is to be met with suspicion. Any such challenge faces
an uphill battle, since we know in advance that it is likely to be
mistaken.5
What I have said about the special status of commonsense beliefs
may strike some as unscientific.6This concern forms the basis of an
important objection that I wish to address in some detail.
The objection may be stated as follows. Throughout the history of
science, progress has been made by the elimination of commonsense
beliefs in favour of scientific theories which show common sense to be
mistaken. Thus, to place common sense in a protected position is to
create obstacles to thoroughgoing critical inquiry of the kind that
enables science to progress in the first place.
My claim that the bulk of our commonsense beliefs may be regarded as true
is distinct in substance from Davidson’s claim that most of our beliefs are
true. My point is not based on a principle of charity. Nor is it based on the idea
that successful linguistic communication may only proceed on the basis of a
shared body of beliefs (e.g. Davidson, 1984). As a realist, I take reality to be
independent of thought. Hence, in principle, all of our beliefs might be false.
But, as a matter of contingent fact, our commonsense beliefs are by and large
true.
6
Or even unphilosophical: one philosopher reacted to my position by saying
that philosophy begins with the rejection of common sense.
5
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Howard Sankey
This objection is well-conceived as a point about widely held
beliefs. There is nothing about being widely held, as such, that grants
widely held beliefs any special epistemic privilege. However, the
objection misses the mark with respect to the basic form of common
sense that I have in mind here. The objection rests on two mistaken
assumptions that I will now identify and reject.
The first assumption relates to the idea that common sense
requires protection from the critical scrutiny of science.
The point that common sense has a privileged status does not
entail that commonsense beliefs are to be protected from critical
scrutiny. On the contrary, they are subject to sustained critical
scrutiny. Commonsense beliefs are put to critical test on countless
occasions each and every day.7Our practical interaction with the world
vindicates a commonsense view of the world every day of our lives.
The point is not that commonsense belief requires protection from
critical scrutiny. As Michael Devitt argues, commonsense beliefs are
among the most highly confirmed beliefs in our belief system precisely
because they are subjected to critical scrutiny on a regular basis.8
The point that common sense is vindicated in practical interaction
with the world may be set within an evolutionary naturalist context.
Commonsense beliefs survive because they have survival value. They
have survival value because they are for the most part true. Our
Sundar Sarukkai has pointed out that our commonsense beliefs are not
tested with the same degree of rigour as scientific theories. I agree in part.
Scientific tests differ in degree of rigour rather than kind. Moreover, the test of
practical application in daily activity may be seen to have a fair degree of
rigour once one takes into account that the measure of practical success is our
continued survival.
8
Devitt, 2002, 22.
7
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Scientific Realism and Basic Common Sense
species could not have survived if the majority of the commonsense
beliefs on which we base our everyday interaction with the world were
false. False belief does not systematically lead to successful action.
Though action based on false belief may succeed, the risks to survival
increase where action is based on false belief. Common sense both
promotes survival and is the result of a process of natural selection.
Our survival constitutes evidence of the reliability of common sense.
Thus, so far from needing protection from critical scrutiny, the role of
common sense in promoting survival shows that it has both withstood
and emerged from the critical scrutiny of evolution itself.9
The second assumption is that in order for science to progress,
common sense must be overthrown and eliminated.
If common sense is understood as widely held belief, scientific
progress may well lead to the overthrow of common sense in that
sense. But, if common sense is understood as basic common sense,
then it is simply not clear that overthrow is what typically occurs in
science. Scientific investigation leads to new insights into the nature of
phenomena that are known to common sense. But in many cases
science does not eliminate common sense at all. Rather, science
explains commonsense phenomena.
Let me illustrate the point with an example from the history of
astronomy. The geocentric idea that the Earth occupies a fixed
The sentiment expressed in this paragraph reflects a broad sympathy to an
evolutionary naturalist approach to epistemic justification. I recognize,
though, that some caution is necessary in expressing this attitude for reasons
articulated by Stich (1990, chapter 3). Mere survival does not entail the truthconducive nature of our belief-forming processes, since there may be
processes which promote survival that do not lead to truth.
9
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Howard Sankey
position at the center of the Cosmos, and that the heavenly bodies
revolve around the Earth, receives support from everyday experience.
It appears to us that the Sun rises every morning and crosses the sky
each day, setting in the evening. At night, the stars, the planets and
the moon become visible, and move across the sky in much the same
way as the Sun traverses the sky each day. But heliocentric astronomy
teaches us that these appearances are misleading. The apparent
movement of the Sun and other heavenly bodies is due to the rotation
of the Earth upon its axis, combined with the movement of the Sun
and other bodies. It is not the Sun that rises and sets. The Sun comes
into view as the Earth rotates. The rotation of the Earth brings the Sun
into view each day.
Geocentric astronomy has a basis in commonsense experience.
Because geocentric astronomy was rejected in favour of heliocentric
astronomy, one might think that heliocentrism entails the overthrow of
common sense. Heliocentrism shows common sense to be false, which
leads us to reject common sense.10 But it is not clear that this is what
happens at all. Our commonsense experience remains exactly as
before. The sun appears to rise, traverse the sky and set each day, and
the objects in the night sky appear to behave in a similar manner. The
appearances do not change. Neither does commonsense experience.11
What changes is what we think happens. Our understanding of
what takes place is altered. Heliocentrism explains why commonsense
experience is the way that it is. It does not show that commonsense
We find a suggestion along these lines in T.S. Kuhn’s discussion of the case.
Kuhn takes heliocentrism to be a “violation of common sense”, since its
adoption requires us to reject the evidence of our senses that the earth is
immobile (1957, p. 43).
11
This is to reject one version of the claim that observation is theorydependent. N.R. Hanson uses the example of Tycho Brahe and Kepler looking
at the sun as it appears at dawn (Hanson, 1958, chapter 1). I agree that they
may describe what they see in different theoretical terms. But, considered at
the level of basic experience, I see no reason to suppose that there is any
difference in how the sun’s movement appears to either Brahe or Kepler.
10
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Scientific Realism and Basic Common Sense
experience is false. It explains why we have the experience of heavenly
bodies moving across the sky. At least in this case, science does not
eliminate
common
sense.
It
teaches
us
how
to
understand
commonsense experience. The assumption that science eliminates
common sense, rather than providing an explanation for such
experience, may therefore be rejected as erroneous.
Of course, a single case of science preserving common sense does
not show that it always preserves it. But there is no reason to suppose
that the present case is in any way an exception. Conformity with
empirical evidence is a standard requirement for theory-acceptance in
science. Because it is primarily observational, empirical evidence
typically forms part of or is at least available to common sense. To the
extent that this is so, conformity of theory with evidence ensures that
science preserves common sense.
We have now seen why the special status accorded to common
sense need not be seen as unscientific. Common sense need neither
be
dogmatically
protected
from
critical
scrutiny
nor
typically
overthrown by scientific advance. Still, it might be thought that appeal
to common sense remains problematic. I will now consider a pair of
objections to the primacy of common sense. The first challenges the
epistemic primacy of common sense. The second challenges its
ontological primacy.
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Howard Sankey
It is sometimes said that common sense is false theory passed
down to us by primitive ancestors. Because common sense is false
theory it is to be rejected as erroneous, rather than granted privileged
epistemic status.
I mentioned before that commonsense beliefs are fallible beliefs
with no guarantee of truth. Even so, the assimilation of common sense
to outmoded theory is to be resisted. This is why it is important to
distinguish common sense from widely held belief. Beliefs to which
members of a society or historical epoch are committed may be
rejected in another society or epoch. But common sense operates at a
more basic level than such transitory commitments. The common
sense enacted in practical engagement with the everyday world is the
natural endowment of humankind, and may be shared with some
species of non-human animals. It is not something that passes in and
out of social and historical fashion. It is a precondition for successful
practical interaction with the world.12
But while there is no need to regard basic common sense as false
theory, the ontology of common sense is also open to challenge.
The world of the commonsense realist is the world of ordinary
middle-sized things with which we causally interact in our daily lives.
But it may be objected that there are no ordinary things. All that exists
I hesitate to say that basic common sense is a human universal. But it is
clear that my view tends in this direction. One reason that I hesitate is that
common sense is fragile. Brain damage may remove some elements of
common sense.
12
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Scientific Realism and Basic Common Sense
are the elementary micro-level entities discovered by modern physical
science. There are no rocks and mountains, tables and chairs. There
are just “atoms and the void”.
The objection is not the sorites point that there are no ordinary
things because things have vague boundaries.13The objection is that
there are no ordinary things because they are made up out of microlevel entities. But this rests on a mistaken view of the relationship
between a thing and its parts.
Ordinary material things are themselves composed of more basic
components, such as molecules, atoms, and elementary particles. To
think that ordinary things do not exist because they are composed of
microscopic entities is to assume that a thing that is made out of other
things is not itself real. But the fact that a thing is made out of other
things does not mean that it is not real. A computer assembled from
component
parts
is
still
a
computer.
Unassembled
computer
components do not constitute a computer until they are put together
to form one. The computer only exists once its component parts are
assembled in a particular way. The ordinary things of common sense
exist despite being composed of myriads of particles too small to see.
With regard to the sorites point, I have only a rather flat-footed response to
make. There is a problem of vagueness in relation to where objects begin and
end. This is a genuine metaphysical conundrum. But this does not alter the
fact that we must still take objects into account in practical affairs. It may not
be clear precisely where the boundaries of an approaching tram or bus lie. But
we had best step out of its path if we wish to avoid injury to ourselves. This
response to the problem seems to me to suffice for the purposes of
commonsense realism, though perhaps not for the purposes of deeper
metaphysical theory.
13
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Howard Sankey
To conclude, I propose that we treat common sense as both an
epistemic and an ontological basis for scientific realism.14
For the scientific realist, science discovers the truth about
observable and unobservable aspects of the independently existing
world. But science itself starts from common sense. And common
sense embodies a realist view of the objects of everyday experience.
Occasionally science may conflict with common sense. But science
does not lead to the overthrow of common sense. Rather, science
explains why commonsense objects appear as they do. It explains why
in some cases the commonsense appearance of things is misleading.
But commonsense realism survives as the basis for our ongoing
interaction with the world. Given common sense, scientific realism is
the most natural position to adopt as an interpretation of scientific
inquiry into the world around us.15
In speaking of an epistemic and ontological basis for scientific realism, I
consciously follow Armstrong, who speaks of our “epistemic base” (1999, p.
77).
15
Ancestral versions of this paper were presented at the University of
Hyderabad, the National Institute of Advanced Studies (Bangalore), the
University of Otago, Université Catholique de Louvain, the University of
Melbourne, La Trobe University and the Rotman Institute of Philosophy
workshop at Grand Bend, Ontario. I am grateful to my interlocutors on these
occasions for feedback which I have attempted to take into account in
preparing the final version of the paper. I am also grateful to the anonymous
referees of this journal whose comments led to improvements in the paper.
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Scientific Realism and Basic Common Sense
Armstrong, D. M., 1999, Romanell Lecture:A Naturalist Program: Epistemology and
Ontology. In: Proceedings and Addresses of the American Philosophical Association, 73,
2, 77-89.
-- 2004, Truth and Truthmakers, Cambridge, Cambridge University Press.
Davidson, D., 1984, The Method of Truth in Metaphysics. In: Inquiries into Truth and
Interpretation, Oxford, Oxford University Press, 199-214.
Devitt, M., 2002. A Naturalistic Defence of Realism. In: M. Marsonet (ed.), The Problem
of Realism, Aldershot, Ashgate.
Eddington, Sir A. S., 1933, The Nature of the Physical World, Cambridge, Cambridge
University Press.
Hanson, N. R., 1958, Patterns of Discovery, Cambridge, Cambridge University Press.
Kuhn, T.S., 1957, The Copernican Revolution, Cambridge, Mass., Harvard University
Press.
Stich, S. P., 1990, The Fragmentation of Reason, Cambridge, Mass., MIT Press.
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