The Chances of Freedom: A Study on Free-Will Libertarianism and Objective Probabilities of Undetermined Actions

Abstract

This thesis aims to answer the question: do free-will libertarians have good reasons to assign objective probabilities to undetermined actions? According to free-will libertarianism, free will is real and incompatible with determinism, and this entails that at least some of our actions are free and undetermined. Many libertarians also endorse an Objective Probability Thesis (OPT), which states that our undetermined actions have objective probabilities attached. Suppose I am trying to decide between doing A or B. For a libertarian endorsing OPT, not only is it undetermined whether I will eventually do A or B, but it is also the case that there is (say) a 0.7 probability that I will do A and a 0.3 probability that I will do B. It must be noted that OPT, albeit compatible with libertarianism, is not entailed by it, as an event can be both undetermined and probabilistically indeterminate. In this thesis, I will then consider and assess the reasons that, from a libertarian perspective, may justify the assignment of probabilities to undetermined actions. I will discuss, in particular, the two arguments for OPT that are found in the literature on libertarianism, which I will call the Argument from Motivation and the Argument from Quantum Probabilities. The first rests on the consideration that often, in situations of choice, we are not equally inclined towards the courses of action open to us, but we are more motivated to choose some of them rather than others. The second argument appeals to the alleged probabilistic character of certain processes in the microphysical realm. I will argue that libertarians should not resort to these arguments because both include premises that are either false, unjustified or at odds with libertarianism. I will show that two assumptions are particularly problematic from a libertarian perspective. One is the thesis that the agent's evaluative ranking of the available options determines the probabilities of the agent's actions. The other is the thesis that the laws of microphysics are complete. Both these claims ill fit with libertarianism, in that they give rise to the problems of irrationality and of microphysical exclusion, respectively. I will conclude that libertarians do not have good reasons to endorse the Objective Probability Thesis. Despite this negative conclusion, the discussion of the Argument from Motivation and the Argument from Quantum Probabilities will allow me to argue positively for what I believe is the best possible version of libertarianism. I will propose and defend a libertarian account of free agency built on two core claims: the thesis that our reasons for action are incommensurable and that it is only via our decisions that some reasons come to outweigh others, and the thesis that the macro-indeterminism is emergent and not derivative of alleged microphysical indeterminacies. The result will be a "deliberative emergentist" libertarian picture that not only does not lend support to talk of objective probabilities of actions but, I will argue, is also better equipped to answer certain traditional objections to libertarianism.

Date of Award	17 Apr 2024
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Ann Whittle (Main Supervisor) & Fraser Macbride (Co Supervisor)