Brain and volition

The Brain and Volition

December 6, 2004

Experience and reason accord to establish that men believe themselves free only because they are conscious of their actions and not of what determines them.

- Benedict de Spinoza

Imagine: inside, in the nerves, in the head - that is, these nerves are there in the brain... (damn them!) there are sort of little tails, the little tails of those nerves, and as soon as they begin quivering... that is, you see, I look at something with my eyes and then they begin quivering, those little tails... and when they quiver, then an image appears... it doesn't appear at once, but an instant, a second passes... That's why I see and then think, because of those tails, not at all because I've got a soul, and that I am some sort of image and likeness...

- F. Dostoevsky

1. The problem of free will and determinism

a. Are we free? If not, who or what determines our actions? Are we responsible for our actions?

b. Rules of the game

i. Discussion must be reasonable, that is, thoughts must proceed to logical conclusion

ii. No appeals to mystery

c. What about dualism?

i. Descartes

ii. The problem of conceiving of a mind that is different than the brain...

iii. ...is that you must figure out how they can interact.

2. "Action and Free Will", Alvin Goldman (in Osherson, Kosslyn & Hollerbach, 1990)

a. Two images of the behaving organism

i. persons as physical-chemical systems

(1) the brain is a physiological organ operating according to principles of chemistry & physics

ii. persons as freely choosing agents

iii. these two views commonly conceived of as in conflict

iv. One way to approach a reconciliation involves developing definitions of different kinds of possibility & impossibility

(1) logical possibility

(a) a square circle is logically impossible

(2) nomological possibility

(a) compatibility with laws of nature

(b) travelling faster than speed of light is logically possible but nomologically impossible

(3) nomohistorical possibility

(a) compatibility with natural laws plus actual history

(b) it is logically and nomologically possible that a rock dropped from a tall building could rise at a given moment in time, but it is nomohistorically impossible because it was dropped

v. based on view that persons are physical systems, determinism is plausible

(1) each successive state of the world is necessary consequence of preceding state of the world

Given for one instant an intelligence which could comprehend all the forces by which nature is animated and the respective situation of the beings who compose it - an intelligence sufficiently vast to submit these data to analysis - it would embrace in the same formula the movements of the greatest bodies of the universe and those of the lightest atoms; for it, nothing would be uncertain and the future, as the past, would be present to its eyes. -Laplace (1820, A Philosophical Essay on Probabilities)

(a) quantum mechanics is not deterministic at subatomic level

(b) nonlinear systems are deterministic but need not be predictable

(2) if determinism is true for human actions, then the only NH-possible actions are those that people actually perform. actions that are contemplated but rejected are not really NH-possible.

(3) thus, if everything we do is NH-required, the view of persons as freely choosing agents must be false, Q.E.D.

vi. two views about this conclusion

(1) defend incompatibilism

(a) determinism & freedom are incompatible

(b) but difficult to avoid dualism along this path

(2) defend compatibilism

(a) both determinism & freedom are true

(3) decision between these two alternatives is not really a scientific, empirical issue but more philosophical

b. The compatibilist account of freedom

i. this view depends on what is meant by freedom

ii. freedom as opposed to bondage or imprisonment, having a wide range of choices

iii. freedom as the ability and opportunity to act in conformity with one's wishes, desires & preferences

iv. thus, inherent in definition of freedom are concepts of ability, opportunity and preference or desire

v. factors comprising performance of an action

vi. defining another sense of possible...

(1) key to compatibilist maneuver is the claim that there is a further sense of possible different from NH-possibility (and nomological and logical possibility).

(2) call it actional possibility; an act may be actionally possible for an agent even though it is not NH-possible at given moment

(3) ordinary thought/language posits many kinds of possibility

(a) e.g., epistemic possibility - possible for all one knows, i.e., this represents the actual possibility of your knowing or believing something about the world that is actually NH-impossible

vii. the compatibilist reconciles determinism with freedom

(1) actional possibility is compatible with NH-impossibility. actions that are NH-impossible are actionally possible

c. Difficulties for compatibilism

i. Choice manipulation

(1) standard component of compatibilist position is that actional possibility should be understood subjunctively (future contingency). it was possible for the agent to do A if, had she preferred A, she would have succeeded in doing it

(2) but if she was unable to choose A, unable to prefer it over alternatives, then she was not really free to do it

(3) thus, there seems to be an element of freedom not captured by compatibilist

(4) imagine a wicked neuroscientist who implanted electrodes in your brain that manipulated your preferences, and preventing you from desiring to do A.

(a) [really, what is the difference between choices caused by external agent (the evil neuroscientist) and choices caused by internal events of life history?]

(5) thus, compatibilism must rule out manipulation of choice and explain how rational, unmanipulated choices are made in a deterministic framework

ii. The paradox of power

(1) suppose determinism is true and that you choose to do some particular thing, A1 (skip class versus attend)

(a) then there was some state of the world (P) in existence before you were born such that from P and the laws of nature (L) it logically follows that you make the particular choice you do. In other words P and L jointly entail A1

(b) the compatibilist asserts that it was actionally possible for you to choose A2 (attend class), that is that you had the power to render A1 false (choose to not skip class)

[if Q ⇒ R, then not R ⇒ not Q]

(d) but not (P and L) involves making false either the state of the world before you were born (P) or the laws of nature (L)

(e) so because it is not in your power to change P or L, then it was not really in your power to not choose A1

(f) hence compatibilism is not valid. QED

(2) However, this puzzle rests on the principle that if one can bring about X, then one can bring about anything that is entailed by X.

(a) this principle if not valid

(b) one can bring about a certain state of affairs without being able to bring about everything entailed by it

(i) e.g., having a party on your birthday entails that you were born. but even though you can bring it about that you have a birthday party, you cannot bring it about that you were born

d. Freedom and choice

i. earlier defined choice as having ability to do either of 2 choices based on your preference

ii. but what of the mugging victim - "Your wallet or your life!"

(1) there are 2 clear choices, but neither is effectuated freely in common sense of the word

(2) but earlier compatibilist position does not distinguish the difference; there is still a free choice between 2 alternatives

iii. Thus, there is a further element to choice & freedom which is value

(1) subjective value categories: negative, positive & neutral

(2) some choices are between 2 evils; other are between 2 good things and others are neutral

(3) but is it valid to invoke this additional concept? do these value categories have any psychological validity?

(a) prospect theory - a theory of choice postulates that agents faced with a decision establish a neutral reference point of zero value.

(b) outcomes better or worse than this zero point are viewed as gains or losses

(i) e.g., using credit card to purchase gasoline. is the 5¢ price difference a "cash discount" or a "credit surcharge"? Credit card companies urge use of the former phrase because it is easier to forego a possible gain than to incur a negative charge

(i) people view losses & gains from a subjective status quo asymmetrically

(4) thus, freedom should include proviso that desired outcome has positive value or gain or at least no negative outcome; choice alone is not sufficient

3. "Is God a Taoist", Raymond M. Smullyan