The problem of akrasia
(weakness of will)
Weakness of
the will (akrasia) has remained an
unsolved philosophical problem since articulated by the ancients. Why do we accord
the present moment more importance than the future, when rationality demands an
Archimedean impartiality between our “present and future selves”? Why would you
judge an action rational, as in your interest all things considered, yet not
perform it?
The problem
of akrasia is one of reconciliation with our commonsense introspective knowledge
that, despite our failings, we clearly can (sometimes) make ourselves do things
that we believe are the better choices. We make (some) rational choices and
conform our behavior accordingly. What stops us from doing so consistently and
biases us for the immediate? Something
limits our ability to decide, but only Freud previously formulated that the
limitation consists of the leaden weight of decisions recently made.
Attempted Solutions
Decision
theory redefines rewardingness as including,
as a feature, the time its utility is
experienced. The utility function describes the decreased value of the same
object enjoyed later, but it doesn’t render it rational. To the extent the
timing of experience is relevant in no other respect, it isn’t rational to
discount time. Why does the rational-choice assumption, that we will do what’s
best for ourselves, fail so miserably when the rewards happen to occur later?
I can recollect only a single theory of why we discount future selves: Derek Parfit takes
the language of “future selves” literally to maintain that they present
to us as the same, in principle, as other persons’ selves, with which we
identify only according to the degree of their relatedness. The cost of Parfit’s
move is the concept of personhood. But while personhood doesn’t deserve to be
part of our ontology, it’s a useful fiction over most of our personal
transactions, failing conspicuously with regard to time discounting. We should
aim to discover why.
Notice
seems not to have been taken by philosophers of what would seem a scientific
solution to the problem of why somewhat rational beings are so akrasic. The
simple empirical answer offered is that we have a tiny daily ration of
willpower. Rational beings can overcome the tendency to discount time by
exerting will power, but they can only do it a few times a day. Our rationality
is limited by our ability to exercise willpower, which is based on a measurable
physical energy source—partly replenished by consuming glucose. The toll decision fatigue takes on people is
shown by the declining performances on real-life
judicial issues, resulting in a change from 70% to 10% favorable
decisions between the beginning and end of the day.
Ego depletion and free
will
Why is
there resistance to recognizing that decisions become harder the more of them you
make? While decision fatigue comports with the introspection that we can make ourselves do some things, it
conflicts with our intuition that we can always do what we want. Ego-depletion
phenomena present yet another breakdown
of the concept of compatibilist free will.
Next essay in series: Implications for the structure of government, welfare economics, and even psychotherapy.
