+ David Hume, Liberty and Necessity An Enquiry Concerning Human Understanding Section VIII
+ Liberty and Necessity intractable dispute: Do we have free will ( liberty ), or are choices causally determined ( necessity )? Hume: Clear definitions of liberty and necessity needed. With definitions, dispute dissolves.
+ Introduction Free will (liberty) and causal determinism (necessity)
+ The doctrine of liberty Human beings have free will
+ The doctrine of necessity aka, causal determinism n Determinism: all events causally determined by antecedent conditions n Laplace s demon: knows laws of nature and present state of universe n Laplace: Demon can predict all future events. n Is a coin toss determined by antecedent conditions? Pierre-Simon Laplace
+ The Clockwork Universe Section VII, Part II quote (pg. 66 bottom)
+ Free will and determinism n Determinism: future events causally determined past events. n Coin tosses? n Compatibilism: Free will and determinism are compatible. n Incompatibilism: Free will and determinism are incompatible. Compatibilism Incompatibilism Determinism soft determinism fatalism Indeterminism compatibilism libertarianism
+ Randomness and freedom n Libertarianism: We are free because determinism is false. n But how do you know determinism is false? n Quantum mechanics: 20 th century theory that allows indeterminacy n Problem 1: Is randomness freedom? n Problem 2: micro randomness cancels out at macro level n Casino example
+ Hume s Enquiry, The definition of necessity Section VIII, Part I
+ Defining determinism Hume: It is obvious that decisions are causally determined by antecedent conditions. (p. 61)
+ The case for necessity First argument: human nature n Humans share basic character. n In-class experiment n Most of your actions would be performed by anyone in same situation. n So, there is a constant conjunction of antecedent conditions and decisions. n Observer of human nature can predict these actions. n So, there is a habitual transition in the mind of an observer between antecedent conditions and decisions.
+ Which is more likely to stay put in a public square? A bag full of money A feather
+ Objection to first argument Human nature doesn t account for everything. n People have different characters because of different: n upbringings and cultures n innate sentiments n In fact, even a single person s character changes throughout her life. n So, human nature necessitates only certain actions.
+ The case for necessity Second argument: peculiar character traits n If you know someone s peculiar moral character, then their actions become even more predictable. n Example: Hume s honest and wealthy friend won t murder him and steal stuff. n This shows: n If you include a decider s peculiar character in the antecedent conditions, then even more actions are necessitated. n If you know the person s character, you ll have a corresponding habitual transition in your mind.
+ Which is more likely to give way? The honest prison guard The thick wall of your cell
+ Objection to second argument Some decisions are unpredictable, even if you know the decider. n Some decisions impossible to predict in advance, even knowing the person s character. n Sometimes a person with an obliging disposition gives a peevish answer. n Hume responds: There s usually an obvious cause. E.g., he has the toothache, or has not dined. n So, these actions at least aren t necessitated by a person s character and situation.
+ A digression about the weather Questions: Could you have predicted where Hurricane Frances would hit land? Why not?
+ The case for necessity Third argument: a secret structure of parts n A coin toss is unpredictable, and so is the weather. But this is due to the secret and complex arrangement of parts not lack of necessity. n When you account for every peculiarity of a person s character, situation, fleeting motivations, etc., actions are predictable and uniform. n Prediction is still impossible in practice, just like with coin tosses and weather. n This shows: n When everything is accounted for, all actions are constantly conjoined with antecedent conditions. n Someone who knew all the antecedent conditions would habitually transition to an idea of the action.
+ Which is more predictable? A person deciding what to wear A tornado deciding on a path
+ Hume s Enquiry, The definition of liberty Section VIII, Part I
+ What is meant by liberty? n Hypothetical liberty: a power of acting or not acting, according to the determinations of the will; that is, if we choose to remain at rest, we may; if we choose to move, we also may. (p. 63) n Does a prisoner in chains have hypothetical liberty? n If your actions are causally determined, do you?
+ Illustration: argument for incompatibilism 1. The laws of nature are not under your control. 2. The conditions of the universe 1,000 years ago were not under your control. 3. If X is causally necessitated by factors outside of your control, then X is not under your control. 4. Therefore, if your action was causally determined by the laws of nature and the conditions of the universe 1,000 years ago, then your action was not under your control.
+ Compatibilist response: reject premise 3 n Prisoner not leaving his cell: necessitated independently of what he wants. n You not murdering your mother for profit, you not sticking your hand in a fire: necessitated by affecting what you want. n Did you choose not to want to stab yourself in the eye? Did you choose not to do it?
+ Hume s Enquiry, Necessity and Responsibility Section VIII, Part II
+ Is necessity compatible with moral responsibility? n You are responsible only for what you can control. (?) n Hume s critic: If your actions are causally determined, then you cannot control them. n Critic: If determinism is true, then nobody is responsible.
+ Hume s Response: Responsibility is compatible with necessity. n If necessity is compatible with liberty, then it is compatible with moral responsibility, too. n Drowning child example n Determinism is required for moral responsibility. n The more stable a person s disposition towards a bad deed, the more harshly we judge. n If a person s actions don t reflect his character, then he isn t as blameworthy. n p. 66 (top)
+ Is God morally responsible for Ted Bundy s actions? n Necessity seems to imply either: 1. Bundy isn t to blame for his actions. 2. God is to blame for Bundy s actions. n Reply to 1: Even if Bundy s actions are part of God s plan, Bundy himself is still blameworthy. n Reply to 2: It s so boundless and ocean of doubt, uncertainty, and contradiction that it has been hitherto to exceed all the power of philosophy.