Welcome back to our series on metaphysics. In our last lesson, we investigated the nature of personal identity, asking what makes you the same person through time and change. We explored whether our identity lies in the continuity of our physical bodies or in the persistent stream of our psychological lives. Now, we turn from the question of what a person is to the question of what a person can do. Specifically, we'll examine one of the most enduring and profound questions in all of philosophy: are our actions freely chosen?
This lesson introduces you to the problem of free will. At its heart lies a deep tension between our powerful, everyday experience of making choices and a scientific worldview that sees every event as the result of prior causes governed by laws of nature. If our choices are just another link in an unbroken causal chain stretching back to the Big Bang, in what sense can they be considered "free"?
Our goal is to map the primary philosophical positions in this debate. By the end of this lesson, you will be able to explain the problem of free will and distinguish clearly between its three main proposed solutions: compatibilism, libertarianism, and hard determinism.
1. The Core Conflict: Free Will vs. Determinism
The problem of free will arises from the apparent clash between two powerful beliefs. The first is our intuitive sense of freedom—the feeling that when we make a choice, we are the author of our action and could have chosen differently. The second is the concept of causal determinism.
Given your background in physics, the idea of causal determinism should be familiar. It is the thesis that the state of the universe at one time, combined with the laws of nature, necessitates the state of the universe at all subsequent times. A classic articulation of this is the thought experiment of Laplace's Demon: an intellect that knew the precise location and momentum of every atom in the universe, as well as all the laws of nature, could calculate the entire future and past with perfect accuracy. While quantum mechanics has challenged this strictly deterministic picture at the micro-level, the macroscopic world of our everyday actions often appears to function in a deterministic or near-deterministic way.
To begin, let's get a formal definition of determinism and see how it sets up the central problem for moral responsibility, which is often seen as dependent on free will.
7.1 Free Will, Determinism and Choice
This video from the University of Oxford, titled "7.1 Free Will, Determinism and Choice," provides a concise introduction to the basic problem.
Please watch the opening segment from the beginning. The speaker, Peter Millican, defines determinism and explains why its apparent conflict with free choice is a philosophically significant problem, particularly for our concepts of blame and praise.
The core issue is this: If determinism is true, then every action you perform was inevitable since long before you were born. How can you be held responsible, praised, or blamed for an action that was a necessary consequence of the past and the laws of nature?
2. Mapping the Landscape of the Debate
The free will debate can be organized by answering two fundamental questions:
- Is the thesis of causal determinism true? (A physical/empirical question)
- Is free will compatible with causal determinism? (A philosophical/conceptual question)
The various answers to these questions define the main positions in the debate. The following diagram provides a clear roadmap.
Following this map, let's define each position carefully.
Incompatibilism: The Fork in the Road
The first major branch in the flowchart separates those who believe free will and determinism are compatible from those who believe they are not. Incompatibilism is the view that free will and causal determinism are mutually exclusive. If one is true, the other must be false. This seems to be the most intuitive starting point for many people. Incompatibilists, however, split into two opposing camps depending on which thesis they choose to accept.
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Hard Determinism: The hard determinist accepts that determinism is true and, because it is incompatible with free will, concludes that we do not have free will. On this view, our feeling of freedom is an illusion.
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Libertarianism: The libertarian (in the metaphysical sense, not the political one) also accepts that free will and determinism are incompatible. However, they insist that we do have free will and therefore conclude that determinism must be false. Our actions, at least some of them, are not causally necessitated by the past and the laws of nature.
Compatibilism: Having It Both Ways?
The other major branch is Compatibilism. Compatibilists deny the central premise of incompatibilism. They argue that free will and determinism can coexist. According to the compatibilist, it is possible for an agent to be determined in all her actions and still be considered free. They achieve this by defining "freedom" not as the ability to act contrary to all prior causal influences, but in other terms, such as acting according to your own desires and values without external coercion.
To solidify these definitions, let's consult a comprehensive encyclopedia entry.
Free Will | Internet Encyclopedia of Philosophy
This section of the IEP article "Free Will" provides clear and formal definitions of the key terms and positions.
Please read the section titled 3. Free Will and Determinism, up to the end of the paragraph defining the various incompatibilist positions. This will cover causal determinism, compatibilism, hard determinism, and libertarianism.
3. The Arguments for Incompatibilism
Why would one believe that free will and determinism are incompatible? The argument often feels so obvious it barely needs stating, but philosophers have formulated it with great precision. The most famous version is known as the Consequence Argument.
Peter van Inwagen, a leading contemporary incompatibilist, provides a very clear and powerful articulation of the core arguments against both determinism and indeterminism. Hearing him explain it will give you a direct sense of the force behind the incompatibilist position.
Peter van Inwagen - What is Free Will?
In this video from Closer To Truth, philosopher Peter van Inwagen explains "What is Free Will?"
First, watch his initial setup of the problem from the definition of free choice. Next, watch his explanation for why free will appears incompatible with determinism. This is the heart of the Consequence Argument: if our acts are necessary consequences of the past and the laws of nature, and we can't change either, then we can't change our acts. Then, watch his argument for why free will also seems incompatible with indeterminism. This is often called the "Luck" or "Mind" argument. If our actions are not determined, they seem to be a matter of pure chance, which doesn't look like control. Finally, watch his summary of the profound dilemma this creates and its connection to moral responsibility.
Van Inwagen presents a powerful dilemma for the existence of free will:
- If determinism is true, our actions are the consequences of things we don't control (the remote past and the laws of nature). Thus, we are not free.
- If determinism is false (i.e., indeterminism is true), our actions are the result of uncaused, random events. This also does not seem to amount to control. Thus, we are not free.
Since determinism and indeterminism are the only two logical possibilities, it seems free will cannot exist. This position is sometimes called free will pessimism or skepticism. It motivates hard determinists (who accept premise 1) and also poses a serious challenge for libertarians, who must explain how an undetermined act is not merely a random one.
4. The Compatibilist Response
How do compatibilists escape this dilemma? They reject the very first step—the Consequence Argument. They argue that the incompatibilist is using a definition of "free will" (or "control," or "could have done otherwise") that is too strong and perhaps even incoherent.
The compatibilist strategy is to argue that freedom does not mean the absence of causation, but the right kind of causation. A free act is one caused by your internal states—your beliefs, desires, and deliberations—as opposed to being caused by external forces or internal compulsions.
For example, a classical compatibilist like Thomas Hobbes might say you are free if you can do what you will, regardless of how your will was formed. The difference between jumping into a lake and being pushed into it is that in the first case, the action flows from your will; in the second, it does not. For a compatibilist, this distinction holds even if your will to jump was itself determined by a chain of prior causes.
More modern compatibilists have developed sophisticated theories to defend this view. A particularly influential line of argument, pioneered by Harry Frankfurt, uses clever thought experiments to suggest that moral responsibility—and thus free will—doesn't require the ability to do otherwise at all. Let's return to the Oxford video for a brief explanation of this idea.
7.1 Free Will, Determinism and Choice
The video "7.1 Free Will, Determinism and Choice" continues by exploring compatibilist responses.
Watch the segment from the Consequence Argument. This part first summarizes the argument you just saw from van Inwagen and then introduces the classical compatibilist re-interpretation of "could do otherwise." Most importantly, it then explains Harry Frankfurt's famous thought experiment intended to show that we can be held responsible for an action even if we couldn't have done otherwise.
Frankfurt's cases suggest that what matters for freedom is not the presence of alternative possibilities, but the source of your action. If you act based on your own reasons and choices, you are free, even if a mad scientist or a deterministic causal chain made it impossible for you to have chosen differently. This shifts the debate from the "Garden of Forking Paths" (requiring alternative possibilities) to the question of "sourcehood" (were you the ultimate source of your action?).
Conclusion
You have now navigated the primary landscape of the free will problem. This is one of the most tangled and persistent areas of philosophy, precisely because each position faces significant challenges, and our fundamental intuitions pull us in conflicting directions.
- Key Takeaways:
- The problem of free will stems from the conflict between our experience of freedom and the principle of causal determinism.
- Incompatibilism is the view that free will and determinism cannot both be true.
- Hard Determinists are incompatibilists who accept determinism and reject free will.
- Libertarians are incompatibilists who accept free will and reject determinism. They face the challenge of explaining how an undetermined act isn't just a matter of luck.
- Compatibilism is the view that free will and determinism are compatible. They argue that freedom consists not in being uncaused, but in being caused in the right way (e.g., by one's own desires and reasons, free from coercion).
- Key arguments like the Consequence Argument (for incompatibilism) and thought experiments like Frankfurt Cases (for compatibilism) are central tools used to probe the logic of these positions.
Preview of the Next Lesson:
Our exploration of free will has repeatedly touched on concepts like causality, the past, and the future. The Consequence Argument, for instance, relies on the idea that the past is "fixed" in a way the future is not. But is this true? In our next lesson, we will dive into the metaphysics of time itself, examining the debate between the A-theory (which holds that there is a real, objective "now" and a fundamental difference between past, present, and future) and the B-theory (which holds that all moments in time are equally real, much like all points in space). Your view on the nature of time has profound implications for your view on causality and, ultimately, on freedom.