In The
Rational Imagination, Ruth Byrne develops an account of imagination
according to which imaginative thought about the way the world could be
shares some of the core principles with rational thought about the way the
world is.  Byrne distinguishes between two versions of this thesis — a
stronger and a weaker one.  According to the stronger version, human
imagination is itself rational, while according to the weaker version,
human imagination merely "shares the same principles as rational thought"
(209).  It is only the stronger version, Byrne points out, that entails that a normative
theory of imagination is possible, i.e., that it is possible to give an
account of good and bad imaginative thought.  The weaker version —
for which The Rational Imagination argues — is more modest.  While it
recognizes the possibility of a normative account of rational
thought in general and that the principles of rational inference are the same
as the principles which ground the imaginative thought, it does not conclude
from these theses that the normative standards of rationality apply equally to human
imagination.

The
main steps of Byrne’s argument (for the weaker claim above) are the following: 
first, she argues, "humans are capable of rational thought," second, "the
principles that underlie rational thought guide the sorts of possibilities that
people think about," and third, "these principles underlie the
counterfactual imagination" (208). 

The
first step of the argument provides the framework for discussing both rational
thought and rational imagination.  Rational thought, Byrne maintains, is a
process of deductive reasoning (a process of inferring a conclusion from
a set of premises in such a way that, if the premises are true, then
the conclusion cannot help but be true as well).  Essentially, then, all
rational inferences can be boiled down to conditional reasoning —
reasoning from a set of the antecedent conditions to a consequent. 
Furthermore, to reason from an antecedent (A) to a consequent (C),
Byrne says, is to understand the conditional ‘if A then C’ in terms of
its truth-functional equivalents, i.e., in terms of a set of propositions that
fall under the two general categories.  While some are going to be consistent
with the conditional claim (e.g., ‘A and C‘), others will be
inconsistent with it (e.g., ‘A and not-C’) and thus constitute a
counterexample to the initial conditional sentence.  In other words, Byrne
argues, to reason at all is to make inferences and to understand these
inferences in terms of sets of "true" and "false
possibilities".

Byrne
qualifies this claim, however.  The logic of reasoning and the psychology
of reasoning are not the same thing.  In spite of the fact that deductive
logic tells us that the proposition (i) ‘If it’s raining, then it’s pouring‘
is truth-functionally equivalent to the proposition (ii) ‘It’s not raining,
but it’s pouring‘, few people actually reason from the truth of (i) to the
truth of (ii).  Instead, from (i) most of us merely infer the truth of a
conjunction:  (iii) ‘It’s raining and it’s pouring‘.  That is,
the rules of logic notwithstanding, people tend to reason economically and to
make inferences based on fewer possibilities than the truth-conditions for ‘if
A then C’ allow.  This economy of reasoning, Byrne points out, is due
(mainly) to our "working-memory capacity" (21), which is not as large
as the set of all possibilities that an inference opens as its truth-functional
equivalents.  Ultimately, according to Byrne, most people do "know that
there may be other true possibilities [aside from the conjunction], but their
thoughts about them remain unformed" (21); thus, while people are "rational
in principle", they sometimes "err in practice" (198).

The
second step of Byrne’s argument — that "the principles that underlie
rational thought guide the sorts of possibilities that people think about"
(208) — is central to The Rational Imagination.  The main thesis
concerning the sameness of principles that guide imaginative and rational
thought rests on Byrne’s account of inferential, deductive reasoning as based
on considering true possibilities.  To understand or to make an inference,
recall, is (first and foremost) to understand the set of true possibilities
that are consistent with it.  Byrne now points out that to understand a set of
true possibilities is, ultimately, to create mentally or to imagine a
set of possibilities that are consistent with the inference at hand.  This
claim crucially brings together rational thought in general and imaginative
thought in particular:  reasoning itself is impossible without the capacity to
imagine the true possibilities with respect to reality, since imagining true
possibilities is constitutive of deductive reasoning.

If,
on the one hand, rational thought is impossible without an imaginative
component, what, on the other hand, can we say about the rationality of
imagination?  In other words, what principles guide us in constructing the sets
of true possibilities consistent with reality?  It turns out, according to
Byrne, that just as conditionals constitute the core of deductive
reasoning in general, it is counterfactual conditionals that are
essential for imaginative thought in particular.  Roughly speaking, imagination
requires us to form thoughts about what might have happened given
X, what could have happened given X, what would be
the case even if X, what would be the case only if X,
etc.  As Byrne herself puts it, "a bridge from rationality to imagination
can be built on counterfactual conditionals.  [Just as conditionals] are a good
example of deductive rationality, counterfactual thoughts are a good example of
everyday imagination.  Counterfactual conditionals," she claims, "combine
both rational and imaginative elements" (30, emphasis
added).

The rational
"element" of counterfactual thought consists in the fact that
imaginative reasoning — much like deductive reasoning in general — proceeds
by considering sets of true possibilities.  The crucial difference between
imaginative thought and the ordinary conditionals, however, is that imaginative
thought involves consideration of a wider set of true possibilities. 
For instance, most people would understand the proposition (P) ‘If
only Andy had been handsome, Becky would have married him’ in terms of two true
possibilities (i.e., possibilities consistent with reality):  (1) the
conjunction of (possible but not actual) facts — Andy is handsome and Becky
marries Andy, and (2) the facts as they are — Andy is not handsome and Becky
is not married to him.  "The subjunctive mood [of P] invites people
to hold in mind the possibility mentioned [i.e., (1)] and also its
negation or another alternative [such as (2)]" (31, emphasis added).

The imaginative
element of the counterfactual conditionals is of equal importance. 
Imaginative thought, Byrne has claimed so far, rests on the counterfactual
conditionals, conditionals the understanding of which involves keeping in mind a
"dual possibility" — (1) the possible (but not actual) facts
consistent with reality, and (2) the implied account of reality as well (e.g., Becky
and Andy not being married since Andy is not handsome).  In the bulk of The
Rational Imagination Byrne turns to the question concerning the principles
that guide us in constructing such true possibilities, possibilities that are
consistent with our knowledge of reality.  The key to understanding how this
imaginative process works, Byrne argues, is in what people take to be "mutable"
vs. "immutable" aspects of reality (36).  It turns out
that most people have a robust (albeit implicit) idea of what features of
reality are mutable and what feature are immutable; furthermore, they use the
immutable features of reality as "anchors" (171) in considering the
true possibilities consistent with facts.  On the other hand, what people take
to be the mutable features of reality are its "fault lines" — the
aspects of reality that are most easily changed in our imaginative thought
about what might have/ could have/ would have been the
case, given the set of (actual) facts.  Thus, The Rational Imagination is
largely dedicated to the study of our psychology concerning the fault lines of
reality:  in chapters 3 –7, Byrne develops a series of arguments that examine
and explain the various fault lines of reality, i.e., that examine and explain
what we take to be "mutable" aspects of reality that are most readily
changed (for their true possibilities) in our imaginative thought.

Byrne’s
Rational Imagination contains a powerful argument for the claim that "imaginative
thoughts are guided by the same principles that underlie rational thoughts"
(xi).  Furthermore, Byrne’s argument to this conclusion rests on a series of
insightful and well-supported interpretations of the nature of human
rationality in general, of the relation between the logical and psychological
makeup of our thought, and of the nature of our imagination.  Due to the fact
that Byrne’s argument entails certain accounts of rationality (taken in its
logical and in its psychological aspects) and of imagination, The Rational
Imagination is bound to interest not only psychologists but philosophers as
well.  As far as the latter go, one of the merits of The Rational
Imagination consists in the fact that, while Byrne does not set out to
develop a normative account of imagination, her argument provides a basis for
such an account.  At the very least, The Rational Imagination challenges
any study of the nature of rational imagination with the task of providing an
account of "good" and "bad" imaginative thought, an account
that must take seriously Byrne’s argument to the conclusion that the principles
of imaginative thought are ultimately the same as the principles of rational
thought in general.

© 2006 Tatiana Patrone

Tatiana
Patrone, Assistant Professor of Philosophy, Montclair State University, NJ

Categories: Philosophical, Psychology