Open Journal of Philosophy
2013. Vol.3, No.1, 9-14
Published Online February 2013 in SciRes (
Copyright © 2013 SciRes. 9
The Value of Beauty in Theory Pursuit: Kuhn, Duhem, and
Decision Theory
Gregory J. Morgan
College of Arts and Letters, Stevens Institute of Technology, Hoboken, USA
Received November 12th, 2012; revised December 15th, 2012; accepted December 31st, 2012
Should judgments of beauty play a guiding role in theoretical science even if beauty is not a sign of truth?
In this paper I argue that they should in certain cases. If we analyze the rationality of theoretical pursuit
using decision theory, a theory’s beauty can influence the utilities of the various options confronting the
researcher. After considering the views of Pierre Duhem and Thomas Kuhn on aesthetics in science, I
suggest that because we value freedom of inquiry we rightly allow scientists some choice in how they
value aesthetic properties of theories and thus some freedom to use beauty to guide their research pro-
Keywords: Beauty; Aesthetics in Science; Decision Theory; Pierre Duhem; Thomas Kuhn; Logic of
Pursuit; Aesthetic Value; Freedom of Inquiry
What is the proper role of beauty in theoretical science?
Those I call aesthetes claim that judgments of beauty can be a
guide to the truth. For example, the philosopher of science
James McAllister argues that because of the way the meaning
of beauty changes over time, there is good reason to think that
beauty is a sign of truth (McAllister, 1996, 1998). The physicist
Brian Greene describes how theoretical physicists often use the
elegance and beauty of theories as “a powerful and insightful
guide” when empirical evidence is difficult to muster (Greene,
1999, p. 167). Others, including me, are skeptical of McAlli-
ster’s claims and the reasonableness of Greene’s optimism
(Morgan, 2005). If McAllister is wrong and beauty is not a sign
correlated with truth, is it possible that beauty plays a non-
epistemic role in science? Are there other functions for beauty
or judgments of beauty in theoretical science? Here is another
area in which the aesthetes and their opponents can debate
(Wechsler, 1978; Curtin, 1980; Tauber, 1997).
One way to approach this question is through the notion of
value. Does beauty have value in science? If so, is beauty one
of science’s fundamental values or does beauty derive its value
from its relation to other values? Can we compare the different
types of value—aesthetic, epistemic, pragmatic, economic etc.—
operative in science? Is there an objective ordering of values in
terms of importance or is the relative importance of the differ-
ent types of value essentially contextual? I will argue that deci-
sion theory allows one to begin to answer some of these ques-
A second way to approach the question of the role of beauty
in theoretical science is to consider its relevance to action in
science. In particular, should the beauty of a theory influence
how a scientist acts regarding the theory? For example, instead
of claiming that its beauty gives us a reason to believe a beau-
tiful theory, as we might if beauty were a sign of truth, the aes-
thete might claim that the beauty of a theory gives a reason to
pursue the theory. In other words, the beauty of a theory might
provide a reason to work out the consequences of the theory,
apply it to more complex systems, add or reformulate its as-
sumptions, or, in general, devote time and money to developing
the theory and its potential evidence, etc., even if the beauty of
the theory is not a reason to believe it. A consideration of rea-
sons for pursuit is said to be a consideration of the “logic of
pursuit” in contrast to the better-known “logic of justification”
(Curd, 1980; Achinstein, 1993). I will argue that beauty can
play a significant role in the logic of pursuit.
In this paper, I will briefly analyze the views of two influen-
tial thinkers on the role of beauty in science: Pierre Duhem and
Thomas Kuhn. Following the survey, I will recast their posi-
tions within decision theory, a framework in which the logic of
pursuit can be made more precise and the role and value of
beauty in theoretical science can be better understood. In each
case, beauty is related to the utility of pursuing a theory, al-
though in different ways. Finally, I will propose that the value
of beauty in science is related to freedom of scientific inquiry.
Pierre Duhem: Beauty Is a Fundamental
Value of Science
Pierre Duhem, in his influential The Aim and Structure of
Physical Theory, has been widely discussed as promoting anti-
realism: the view that science does not, and should not, aim to
discover truths about reality (see for example, Musgrave, 1999).
However, Duhem’s position is subtler than usually thought. He
thinks that physical theory “represents,” as simply, completely,
and exactly as possible, a set of experimental laws and that it is
impossible not to think that the resulting “natural classification”
of experimental laws corresponds to “real affinities among the
things themselves” (Duhem, 1954: pp. 19-26). Nonetheless, he
argues the representation of experimental laws neither explains
reality nor “conforms” to it. Furthermore, in a spirit reminiscent
of David Hume, Duhem claims that we cannot prove that nature
possesses the real affinities suggested by the relations in the clas-
sification although we cannot help but think such connections
exist. Thus, he does not think that the aim of theoretical science
is to reveal truth in any realist sense, although the structure of
physical theory may “hint” at the real affinities of things (Du-
hem, 1954: p. 30). Rather, he suggests that the fundamental va-
lue of theoretical science is a beautiful orderly classification
and an economical representation of otherwise disparate expe-
rimentally discovered physical laws:
Order wherever it reigns, brings beauty with it. Theory not
only renders the group of physical laws it represents easier to
handle, more convenient, and more useful, but also more beau-
It is impossible to follow the march of one of the great theo-
ries of physics, to see it unroll majestically its regular deduc-
tions starting from initial hypotheses, to see its consequences
represent a multitude of experimental laws down to the small
detail, without being charmed by the beauty of such a construc-
tion, without feeling keenly that such a creation of the human
mind is truly a work of art (Duhem, 1954: p. 24).
For Duhem, the orderly representation and classification that
is theoretical physics is beautiful.
We must make some interpretative moves before we can
claim that Duhem thinks that creation of beautiful theories is a
fundamental value of science, however. To see this point, con-
sider two senses of value of science. In the first sense, if X is a
value of science and Y is coextensive with X then Y is also a
value of science. In the second sense of value, if X is a value of
science and X is co-extensive with Y, it does not follow that the
value of science is also Y. Which of these two senses is more
plausible for Duhem’s conception of beauty? If Duhem thought
that there was only a contingent connection between order and
beauty, then one could argue that Duhem’s notion of the aim of
theoretical science is not to reveal beauty, necessarily, but to
articulate order. Nonetheless, it is more plausible that Duhem
took the connection between beauty and order in theoretical
science to be necessary. For example, one could argue that for
Duhem, theoretical beauty just is theoretical order. Thus on a
plausible reading of Duhem, he claims that a beautiful physical
theory realizes a fundamental value of science to a greater ex-
tent than an ugly alternative.
Thomas Kuhn: Beauty as Subjective Value
In his Structure of Scientific Revolutions, Kuhn claims that
“aesthetic considerations” can lead scientists to reject an old
paradigm in favor of a new one (Kuhn, 1970: p. 155). He says
little about what he means by “aesthetic considerations,” but in
his postscript, he gestures at judgments of simplicity, consis-
tency, and plausibility (Kuhn, 1970: p. 185). In a later article,
Kuhn considers aesthetics in science more directly. On the rela-
tion between art and science, Kuhn writes:
Undoubtedly, … considerations of symmetry, of simplicity and
elegance in symbolic expression, and other forms of the mathe-
matical aesthetic play important roles in [art and science]. But
in the arts, the aesthetic is itself the goal of the work. In the
sciences it is, at best, … a tool: a criterion of choice between
theories that are in other respects comparable, or a guide to the
imagination seek ing a key to th e solution o f an intr actable puzzle
(Kuhn, 1969: p. 342).
Although Kuhn probably would not have put it this way, the
quotation suggests two roles for aesthetics in science: one in the
context of justification and another in the context of discovery.
Additionally, as Margolis argues, it seems overly restrictive to
confine these two roles to revolutionary science as Kuhn does
(Margolis, 1997: p. 193). It is the former role in theory choice
that is pertinent to our current discussion—how aesthetic con-
siderations supposedly guide us to adopt one theory over another.
Kuhn’s notion of theory adoption or theory “choice” is ambigu-
ous. It can be interpreted to mean adopt-as-true or to mean
adopt-as-worthy-of-pursuit. Kuhn is usually interpreted as in-
tending the latter.
For Kuhn, some properties responsible for a theory’s beauty
are the same properties of theories or “theoretical values” that
feature in standard lists of criteria for theory choice. Kuhn
himself mentions five criteria for “evaluating the adequacy of a
theory”: accuracy, consistency, scope, simplicity, and fruitful-
ness (Kuhn, 1973: p. 323). He acknowledges that the list is in-
complete and that there are differences in how we interpret each
one as well as further difficulties in assigning relative weights to
each criterion. Presumably, we could add further criteria such as
consilience, explanatory power, elegance, computational trac-
tability, visualizibility, etc., as well as more specific properties
of theories. Not surprisingly, there is not universal agreement
over which, if any, of these criteria for theory choice are ae-
sthetic. Further, even if a theory is beautiful because of its
simplicity say, it does not follow that all cases of simplicity are
aesthetic. Nonetheless, Kuhn’s remarks suggest that he thinks at
least some of these criteria are aesthetic, and additionally, that
the particular balance between them can be an aesthetic
For Kuhn, members of a scientific community share, among
other things, a common set of values. Some of these values are
aesthetic. For example, a specific interpretation of the meaning
of simplicity might involve an appeal to what is beautiful.
Suppose that a scientist accepts one theory TB over a competing
TU because TB is more beautiful than TU. It does not follow that
she believes TB, since for Kuhn, theory acceptance need not
involve belief. Rather it is a commitment to the theory that is
based on values that define the scientist as being a member of a
particular scientific community. Now one might worry that the
values within scientific communities are not objective but change
over time and from person to person. Kuhn is receptive to this
… values may be shared by men who differ in their applica-
tion. Judgments of accuracy are relatively, though not entirely,
stable from one time to another and from one member to an-
other in a particular group. But judgments of simplicity, con-
sistency, plausibility, and so on often vary greatly from indi-
vidual to individual (Kuhn, 1970: p. 187).
Aesthetic values are more likely to be of the latter more
variable type of value and thus a pernicious subjectivism looms.
Kuhn replies to this potential problem with the following two
First, shared values can be important determinants of group
behavior even though the members of the group do not apply
them in the same way… Men did not paint alike during the
periods where representation was a primary value, but the
developmental pattern of the plastic arts changed drastically
when that value was abandoned… Second, individual vari-
ability in the application of shared values may serve essential
functions in science… If all the members of a community re-
sponded to an anomaly as a source of crisis or embraced each
new theory advanced by a colleague, science would cease
(Kuhn, 1970: p. 188).
Kuhn’s response to the problem of subjectivity invites many
Copyright © 2013 SciRes.
more questions. What determines the limits of the variation in
value application? Would science really cease if there were
perfect agreement on the interpretation and application of val-
ues? Surely there could be disagreement over how to interpret
the theories themselves (as opposed to merely disagreement
over the criteria of choice). In addition to intra-community vari-
ation in values, there can be inter-community variation. Mem-
bers of different paradigms may share wildly different concep-
tions of beauty. This is one reason that Kuhn does not talk in
terms of “reasons for belief” when discussing theory choice
since it is possible for scientists from different paradigms to
adopt or choose different theories given the same evidence
based on the same values but differentially interpreted and/or
weighted. Indeed it is possible on Kuhn’s view that for any two
theories of a given phenomena, T1 and T2, if scientist S1 from
paradigm 1 adopts T1 over T2, then scientist S2 from paradigm
2 adopts T2 over T1. For many philosophers who desire a more
robust sense of objectivity, this result renders Kuhn’s position
overly liberal. Nonetheless, Kuhn does illustrate how aesthetic
value might play a role in theory acceptance, even if beauty is
not a sign of truth and he takes seriously the variation in how
aesthetic properties are weighted.
A Decision-Theoretic Analysis
Decision theory allows one to analyze the role of beauty in
the logic of pursuit. I will develop an idea of Hempel (1965),
who suggests we quantify the utility of the possible outcomes
of research and treat theory acceptance as a question of decision
theory. With this analysis in place, the relations among the
thinkers will be clearer.
The overarching normative principle of decision theory is
that one should act in such a way as to maximize expected util-
ity of the action. To see how this principle is applied to the
question of the practical relevance of beauty, consider a case
where we are considering pursuit with respect to two mutually
exclusive theories, one beautiful TB and one ugly TU. To keep
the analysis relatively simple, let us assume that for each theory
one has to choose simply to pursue it or not1. (A more general
analysis might consider deciding the degree ri to pursue each
theory Ti). The relevant magnitudes can be summarized in Ta-
ble 1. There is no column for both TB and TU being true in Ta-
ble 1 since we assumed that the two theories were mutually
exclusive. The probabilities sum to unity: P(TB) + P(TU) +
P(~TU & ~TB) = 1. The expected utility of an action is calcu-
lated by summing the utilities weighted by the probability that
the appropriate state of affairs obtains.
The expected value of pursuing TB (and not pursuing TU)
consists of three terms:
 
 
EPursue Tonly
PTUPursue Tonly/T
PTUPursue Tonly/T
P~ T& ~ TUPursue Tonly/~ T& ~ T
Table 1.
A decision theoretic matrix for theory pursuit. U(X/Y) symbolizes the
utility of doing X given Y is true.
B is true TU is true Both are false
P(TB) P(TU) P(~TU & ~TB)
TB onlyU(Pursue TB only/TB)U(Pursue T
B only/TU) U(Pursue TBonly
/~TU & ~TB)
TU onlyU(Pursue TU only/TB)U(Pursue T
U only/TU) U(Pursue TU only
/~TU & ~TB)
neither U(Pursue neither/TB)U(Pursue neither/TU) U(Pursue neither
/~TU & ~TB)
both U(Pursue both/TB) U(Pursue both/TU) U(Pursue both
/~TU & ~TB)
Analogous equations hold for the three other possible actions.
The most reasonable course of action has the highest expected
utility. A more reasonable course of action has a greater ex-
pected utility than a less reasonable course of action. To calcu-
late the maximal expected utility and hence the most reasonable
course of action, one needs more information than merely the
probabilities that are used in determining what to believe. In
theory, one calculates the expected utilities of all the possible
actions (i.e., the four actions above in our case) and the action
with the highest expected utility is the most reasonable one.
Decision theory shows a way in which beauty can be relevant
to how scientists should act toward theories, even if it is irrele-
vant to the probabilities of theories. If beauty influences the
values of the utilities, it can influence the most reasonable
course of action.
The use of the decision-theoretic framework to illuminate the
role of aesthetics relies on a number of contestable assumptions.
Perhaps the most significantly, decision theory assumes that the
expected net benefit, a single number, can adequately represent
the net value of an action. Pursuing a theory might create dif-
ferent types of value—producing knowledge, making predic-
tions, creating a beautiful object, making possible technical pro-
gress, etc.—and decision theory assumes that these different
types of value can somehow be summed. An opponent of this
approach might argue that different sorts of value cannot be
summed in this way. He or she could argue that the different
sorts of value are incommensurable and that there exists no
one-dimensional measure that captures a “total” amount of
value or utility. In response, let me make three points. First, we
often do place a single numerical value on beautiful things, for
example, in art auctions. Second, when using decision theory,
we often do not need to assign definite numbers to the utility
values in order to work out the most reasonable course of action.
Under certain conditions, just the relative differences in utility
are sufficient to determine which course of action is most rea-
sonable. Finally, when we choose to act one way rather than
another, we have, in effect, assigned relative weights to con-
flicting values. Although we might not be conscious of using
any rules to make the choice, this unawareness does not mean
that the action cannot be accurately described as following in-
ter-value balancing principles.
1Rota (1997) makes the point that, in mathematics at least, one does not
directly pursue beauty if one hopes to create it. If such a view were correct
of all of empirical science, it would undermine the goal of this paper. I
assume that the choice is between pursuing two theories that have been
partially developed such that we can determine that one is beautiful and one
is not.
Two Decisions: By the Society and by the
The question of inter-value balance is a difficult one. I sug-
gest that to make some progress we separate at least two dis-
Copyright © 2013 SciRes. 11
tinct projects that so far have been conflated. First we can con-
sider the above matrix as representing the decision parameters
of a single scientist considering which theory to pursue. Second,
we can consider the above matrix as representing the decision
parameters of a larger group of people, and at the extreme,
society as a whole. When issues of how society should fund
research are used to justify study of “the logic of pursuit,” these
two distinct projects risk being conflated. At the national level,
funding agencies make these decisions on behalf of the society.
The utility values for a single scientist and for society need not
be the same. In fact, we would expect them to differ because we
would expect different types of outcomes of theoretical pursuit
to be relevant to different degrees and therefore the utilities for
society and the individual scientist to be different. Of course,
this does not mean that many of the consequences valued by the
scientist will not be valued by society too. For example, we
would expect that the aesthetic pleasure that a scientist gains by
pursuing a theory to be weighted more highly by the individual
scientist pursuing the theory than by society at large. On the
other hand, contemplation of the beautiful theories of science
could be argued to be a social good that funding agencies
should take into consideration. Nonetheless, it would be an
unlikely coincidence if the degree of value attributed to pursuit
of a beautiful theory were the same for the person pursuing the
theory and society at large.
Inter-Value Realism and Inter-Value
On either the individualistic or the social project, the crux of
the decision theoretic rendition turns on the relative amounts of
the relevant utilities. Philosophers might be grouped into two
groups according to how they approach this problem. First,
there are the inter-value realists. They hold that the correct
balance among different types of values is independent of what
we take the balance to be. In other words, there is a correct
balance to be discovered and whatever this balance is, it does
not change if we change what we take it to be. Opposed to the
inter-value realists are the inter-value anti-realists. They hold
that the correct balance among different types of value depends,
at least in part, on what we take them to be. They would argue
that the facts needed to justify the realists’ balance do not exist.
For them, there is no correct balance to be discovered; rather it
has to be invented by us. The distinction between inter-value
realists and anti-realists is vague insofar as the referent of “we”
in the above distinction is vague. To be more precise, let “we”
refer to the individual scientist in question in the individual
decision problem and refer to society in the societal decision
problem. Notice that it is not inconsistent to be a realist with
respect to one of these decision problems and not with the other.
The instrumental rationality that is usually assumed by decision
theorists is neutral on the inter-value realism/antirealism issue.
Stripped down decision theory does not provide any constraints
on the utility values, nor a way to determine them. Rather fun-
damental values in the form of utilities are taken as given, and
action is judged reasonable relative to the utilities. This is true
of both the individual and the social decision problems.
Duhem, Kuhn, and Decision Theory
Keeping in mind the decision theoretic approach, the distinc-
tion between an individualistic and societal perspective, and the
distinction between a realist and an anti-realist view of utilities,
let us return to the views of Duhem and Kuhn. Can their views
be captured within decision theory? Can we categorize them
neatly with the distinctions I have drawn?
Let us begin with Duhem. He thinks that beauty accompanies
the order that scientists should aim for in constructing their
theories. His view is that order is a fundamental value of theo-
retical science does not depend upon what we take the funda-
mental values of science to be. Neither do the utilities associ-
ated with pursuing a given theory. Duhem, then, on my account,
is an inter-value realist. In fact, he is an inter-value realist at
both the individual and the societal levels. His position is most
apparent when he discusses the imaginative yet shallow “weak-
minded” English scientist. He chastises English scientists, no-
tably Sir William Thomson and James Clerk Maxwell, for pro-
viding a series of disconnected models rather than an ordered
theoretical science. He clearly thinks that if a scientist had to
choose between pursuing an abstract beautiful “French” theory
and a shallow ugly “English” one, she should pursue the French
one. This truth is independent of whether we take the utility of
the English type of theory to be superior, as the English scien-
tists he mentions did. In other words, Duhem thinks that the
English scientists are wrong to think that their way of doing
things is better. Science as a whole, and individual scientists in
particular should emulate the French scientist. To put Duhem’s
position in the language of decision theory, he thinks that
E(pursuing TB only) > E(pursuing TU only) in large part be-
cause TU does not possess the order that characterizes good
theories. Can we attribute to Duhem views about the utility
values we find in the decision matrix? This attribution is made
difficult because the various values are predicated on different
truth-values of TB and Tu. As mentioned above, standardly
interpreted, Duhem does not believe that theories are true or
false, in the sense that they correspond with the world. Let us
assume that where we consider the probability of a particular
theory, Duhem understands it to mean the probability of the
theory containing “natural affinities,” to use his language. Du-
hem, I claim, would argue that it is impossible for a theory
without order to show “natural affinities.” If this is so, then the
utility associated with the pursuit of a true ugly theory is irrele-
vant to practical reason, i.e., U(Pursue TU only/TU) multiplied
by 0 = 0. Indeed, at root Duhem’s desire to pursue theories with
order and beauty seems to be driven by a metaphysical belief
that the world has “ontological order” and that this order can
only be captured by an orderly physical theory; thus p(TB) >
p(TU). Duhem is quite conservative in this regard.
Nonetheless, if we assume that p(TU) > 0, and if decision
theory can be applied to Duhem’s position, then we need values
of pursuit given that TU is true. Duhem does consider whether
the ugly English models are fruitful for discoveries (Duhem,
1954: p. 93). After a brief historical survey, he concludes that,
“the share of the booty it [the use of ugly mechanic cal models]
has poured into the bulk of our knowledge seems quite meager
when we compare it with the opulent conquests of the
[French-style] abstract theories” (Duhem, 1954: p. 99). In fact,
although there have been some discoveries with the use of
models, their use of these models may even “obscure discover-
ies already made.” Furthermore, the beautiful abstract theory
has the extra utility of being an orderly classification and the
extra utility due to the “esthetic emotion” that it produces (Duhem,
1954: p. 24). In the language of decision theory, Duhem claims
U(Pursue TB only) U(Pursue TU only) and perhaps even
Copyright © 2013 SciRes.
U(Pursue TB only/TU) > U(Pursue TU only/TU).
Relative to Duhem, Kuhn is a radical. He is an inter-value
anti-realist, at both the individual and societal levels. He argues
that the balance between different values varies across time and
among scientists. This variation in values promotes efficient
science, since diversity and competition between different per-
spectives drives science forward, or so Kuhn argues. How an
individual scientist (correctly) balances the different types of
value is in part dependent on the importance that scientist
places on the values. Kuhn argues that “features of individual
personality and biography” explain much of the variation
among scientists (Kuhn, 1970: p. 185). The scientist is con-
strained to some degree by her “professional initiation” into a
paradigm: to remain within her paradigm, her balance cannot
vary significantly from the paradigm average, but nonetheless,
there can be personal differences among different members of
the same paradigm. At the societal level, Kuhn does not attri-
bute science as a whole with fundamental values beyond the
values that all scientists share. Presumably these values are
quite weak as any interesting value has associated with it dis-
agreement that fractures the scientific community into more
specific scientific communities. Kuhn does, however, think that
paradigms are constituted by largely shared values. The par-
ticular balance and interpretation of the values constituting a
paradigm are not determined top-down, but rather emerge as a
rough consensus among member scientists. Kuhn’s position can
be captured within decision theory very well. Each scientist’s
set of values applied to a particular decision is represented by a
set of utility values and the paradigm values can be represented
by the mean and standard deviation of the population. Typically
we would expect members from a single paradigm to largely
agree over which theory should be pursued.
Kuhn can accommodate the example of the anti-aesthete
within his framework. In fact, there is nothing within his sys-
tem that prohibits a community of anti-aesthetes constituting a
paradigm. Some may argue that this is a weakness of his sys-
tem—that it is too loose to rule out cases such as this. Indeed,
in his 1970 postscript, Kuhn adamantly defends his position
from charges of irrationality made by Lakatos and others. A
charge of irrationality would be valid if scientists could give up
a value like consistency, perhaps, but here we are discussing
how to react to aesthetic features of our theories of the world.
In fact, one could make the case on behalf of Kuhn that if every
scientist chose to work on the beautiful theory and not the ugly
alternative, that this tendency would bias scientific practice as a
whole and delay us developing a true ugly theory, if in fact the
world is best described by an ugly theory. That a small per-
centage of scientists do concern themselves with counting la-
dybug populations is not a bad thing.
Beauty and the Freedom of Inquiry: A Proposal
Let me end by sketching the beginnings of an inter-value an-
ti-realist view at the individual level. As a society we allow in-
dividual scientists the freedom to formulate and prioritize their
own values. There are some constraints that are often codified
by legal and ethical imperatives, but generally society does not
dictate methodological values to individual scientists and nei-
ther should it. Each scientist is given the freedom to choose the
exact balance between different kinds of value and to use this
balance to guide his or her research program. My position is
clearly inter-value antirealist as the “correct” balance between
values for an individual scientist is determined by what the
individual scientist takes them to be. Of course, there are incen-
tives for an individual scientist not to choose a balance too far
from her community norm if she wishes to be a successful
member of that scientific community. Two ways of justifying
this attitude toward its scientists are open. One could argue that
granting such freedom to scientists leads to efficient science, or
one could argue that the value of the freedom granted is its own
justification. The former type of justification lies behind Paul
Feyerabend’s famous crusade against fixed rules of methodol-
ogy (Feyerabend, 1975; Lloyd, 1996). Although he is concer-
ned more with the free choice or rejection of methodological
rules, Feyerabend’s writings also support the idea of freedom of
choice of value. The latter option makes freedom of inquiry, in
the sense of choice of values as well as choice of project, a fun-
damental value of science.
Beyond being an inter-value antirealist position, how does
this view fit into the decision theoretic framework I presented
earlier in this chapter? There are some difficulties in represent-
ing the value of freedom within the decision theoretic frame-
work. On the other hand, there is synergy also. For decision
theory to be useful, one has to presuppose that the decider is
free to choose any of the options represented (For a related
point, see Sen, 2002: p. 593). If there were no freedom, then it
would be futile to calculate the most rational course of action
because it could not be chosen. I am, however, proposing a
more radical freedom, not the freedom to choose what theory to
pursue, but rather to choose which properties of a theory are
valuable and to what degree. More specifically, I suggest that
individual scientists can choose the degree to which they value
beautiful properties of theories. On my view, theoretical pursuit
can be seen as a two-stage process: first choose the properties
that you value and their relative strength; then apply these val-
ues to select the theory to pursue. The second stage is simply an
application of decision theory as I have presented it earlier.
Decision theory has its limitations. If we turn our attention to
how to use decision theory to decide what properties of theories
to value with high utilities, we confront the possibility of an
infinite regress. In other words, to use decision theory to choose
which properties of theories to value, we need utility values for
adopting these utility values and we merely push the problem
back one level. How do we determine these 2nd order utility
values? To apply decision theory requires that we have 3rd
order utility values. And the infinite regress takes hold. There
are additional problems applying decision theory to the choice
of utility values. Consider the case where we choose between
two inequalities: 1) U(TB/X) > U(TU/X); and 2) U(TB/X)
U(TU/X). Applying decision theory to this problem requires
that we use probabilities such as p[U(TB/X) > U(TU/X)]. But
what do such probability statements mean? If one is an in-
ter-value realist, these statements mean the probability that the
value of utility pursuing TB is greater than pursuing TU. For the
inter-value realist these probabilities are defined independently
of what the individual scientist takes the utilities to be. For the
inter-value antirealist, however, these probabilities are not in-
dependent of what the scientist takes the utilities to be. But
what the scientist takes the values to be just is what the decision
problem is trying to solve. Thus, the inter-value anti-realist en-
counters a circularity in determining the probability values for
the above decision problem: the decision depends on the prob-
ability values, which in turn depend upon the decision.
The freedom to choose utility values cannot be entirely gov-
Copyright © 2013 SciRes. 13
Copyright © 2013 SciRes.
erned by decision theory. There must also be what might be
called the spontaneity of individual values. That a particular
scientist chooses to pursue a beautiful theory over an ugly the-
ory (because she has chosen to value beauty over ugliness) is a
right that we as a society respect. No doubt that there are em-
pirical connections between certain theoretical properties that
are candidates for values and the practical outcomes that soci-
ety values. These connections are exploited by funding agen-
cies on our behalf to promote biases in research that hopefully
lead to more valuable outcomes for future society. However,
many of the ultimate theoretical values are fixed neither by
society nor by reason, and we add to their value by allowing
individual scientists to freely choose them (see Sen, 2002,
Chapters 20 and 21, for more on the value of freedom of pro-
cess.) A controversial consequence of my position is that it
would not be irrational for an individual scientist (the anti-
aesthete) to pursue the uglier alternative, if her choice of values
dictated this course of action. Kuhn might be right that many
scientists’ values are mostly fixed by their professional history
and context. But scientists are not entirely passive. They have
the ability to choose the value of beauty and thus how to react
to it. An anti-aesthete, although rare, is not necessarily irra-
To return to an opening question of this paper: Is beauty a
fundamental value of research? Not necessarily. There is no
global answer. However, locally many scientists choose it to be
one of their implicit fundamental values. Ceteris paribus, they
would rationally pursue a beautiful theory over an ugly rival.
This is true even if beauty does not lead to any more practical
benefits. For them, the value of beauty exemplifies their right to
the freedom of inquiry. On the flip side of the coin, I suggested
that an anti-aesthete who reverses the typical aesthetic ordering
also illustrates society’s willingness not to restrict the freedom
of inquiry. Feyerabend argues that this pluralism is good for
inquiry and society as a whole. I suggest that it also could be
justified by the value of freedom of inquiry itself.
Summary and Conclusion
If beauty were irrelevant to a theory’s truth or probability,
would beauty be irrelevant to the practice of guiding theoretical
science? No, not necessarily. Decision theory shows how aes-
thetic value can influence the utility of theory pursuit. For many
scientists, the beauty of a theory increases the expected utility
of pursuing the theory. For them, there is an important sense in
which beauty is a fundamental value of their science. I argued
that we should distinguish at least two different decisions: 1)
the decision confronting an individual scientist over what the-
ory to pursue; and 2) the decision confronting a society over
what research to fund and promote. The role of beauty need not
be the same in both cases. Duhem and Kuhn argue that aes-
thetic value should influence how scientific research should
proceed. Their insights can largely be captured within the deci-
sion theoretic framework. Kuhn disagrees with Duhem over the
status of the various utilities associated with pursuing a given
beautiful theory. Duhem believes that the balance between
different types of value is independent of what we take it to be.
He is an inter-value realist. He thinks that certain aesthetic val-
ues are fixed by the nature of (correct) science. Kuhn, on the
other hand, promotes the importance of individual variation and
argues that the correct balance between different types of value
depends upon one’s personal biography. Alternatively, I sug-
gested that one could argue that the value of freedom of inquiry
justifies a scientist’s right to value aesthetic properties in a
manner that she sees fit, given certain constraints. On this sug-
gestion, freedom of inquiry underwrites an inter-value anti-rea-
lism at the individual level. One consequence—and one vir-
tue—of my view is that some scientists can reasonably choose
to pursue ugly theories over otherwise similar beautiful alterna-
I thank Peter Achinstein and Christopher Smeenk for com-
ments on an earlier draft. Jennifer McBryan helped with stylis-
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