Free Will Beyond Confusion: What Matters for Criminal Law, Forensic Practice, and Everyday Life

The enduring debate surrounding free will, a philosophical and scientific quandary that has captivated thinkers for centuries, continues to spark intensive discussion across psychology, neuroscience, philosophy, and law. While the modern era, particularly since the "Decade of the Brain" in the 1990s, has seen a surge in research and discourse on this topic, the foundational arguments have deep historical roots. As far back as the 19th century, German-speaking intellectual circles were already engaged in robust debates, even calling for significant reforms in criminal law based on emerging deterministic views of human behavior.

One prominent figure in this early discourse was the German-Swiss scientist Carl Vogt (1817-1895). Vogt, a widely recognized public intellectual, boldly asserted that free will was an illusion. He argued, "Free will does not exist and with it no responsibility such as morality and the criminal justice system […] want to impose on us. At no moment are we masters of ourselves, of our reason, of our intellectual powers, any more than we are masters of whether our kidneys should secrete or not secrete. The organism cannot control itself; it is controlled by the law of its material composition. What we think in a moment is the result of the current mood, the current composition of our brain" (Vogt, 1852, p. 445f). Vogt famously compared the brain’s production of thoughts to a kidney’s secretion of urine, positing that all mental activity, like bodily functions, was governed by immutable natural laws. This perspective, which left no room for genuine free will, presaged the ideas of later thinkers like Sigmund Freud by nearly three-quarters of a century.

From a contemporary viewpoint, Vogt would be classified as a "hard determinist"—an individual who believes that the universe, or at least the nervous system, operates under a completely determined framework, rendering free will impossible. Neurophilosophers have, in turn, categorized these positions into a 2×2 matrix based on two binary variables: determinism (whether events are causally predetermined) and free will (whether individuals possess the capacity for genuine choice). The matrix includes:

• Compatibilism: Assumes determinism but defends free will, defining it as freedom of will through internal desires, beliefs, and conscious deliberation.
• Libertarianism: Assumes indeterminism and defends free will, viewing it as a metaphysical force that directs our decisions in a naturally undetermined world.
• Hard Determinism: Assumes determinism and denies free will, as articulated by Vogt.
• The fourth position, which denies both determinism and free will, is rarely adopted due to its perceived lack of explanatory value.

The author of this opinion piece, Stephan Schleim, contends that the persistent focus on these abstract philosophical distinctions, particularly the debate over determinism, often distracts from more practical considerations. Schleim highlights three key points:

Firstly, the very definition of "will" remains elusive. As the analytic philosopher Gilbert Ryle (1900-1976) noted, "volition" is an "artificial concept" not commonly used in everyday language. Its meaning often overlaps with questions of voluntary action, intention, and responsibility.

Secondly, the debate frequently hinges on whether the world is deterministic, meaning whether one could have acted differently under precisely the same circumstances. While computer science defines deterministic algorithms by their consistent output for identical input and internal states, and quantum physics grapples with the inherent indeterminacy of states, Schleim finds these questions practically unproductive. In a dynamic and complex environment like our constantly changing world and the intricate human brain, experiencing the exact same conditions twice is impossible. Furthermore, truly random decisions would not constitute a meaningful form of free will.

Thirdly, Schleim argues that compatibilism merely shifts the problem. While defining free will as conscious decision-making aligned with one’s preferences seems appealing, it fails to address the origin of those preferences. For instance, how free is an individual if their desires and beliefs are shaped by an upbringing that instills prejudice? Arthur Schopenhauer’s famous aphorism, "You can do what you want, but you cannot want what you want," encapsulates this challenge.

Free Will in Criminal Law, Forensic Practice, and Real Life

Schleim asserts that the confusion surrounding free will stems from assuming its existence as a distinct entity. Instead, he proposes that in legal and forensic practice, and indeed in everyday life, the focus should be on concepts like insight and conscious control, rather than abstract notions of free will.

Legal Frameworks and Responsibility:
Both German and U.S. criminal law, along with many other legal systems, operate on the presumption that individuals are generally rational beings responsible for their actions. For example, under German law, individuals over the age of 14 are held criminally responsible unless specific impairments—such as pathological disturbances of insight or control—are present. The key legal question is not whether someone possessed "free will," but rather if they could distinguish between right and wrong and act according to that understanding.

U.S. criminal law, similarly, requires a causal link between the criminal act (actus reus) and the criminal intent (mens rea). If an intended victim dies from an unrelated cause before the perpetrator’s action takes full effect, the crime of murder cannot be established because the causal chain is broken. Legal exculpation typically arises from legally defined defenses such as duress or specific mental disorders.

In criminal proceedings, judges and experts therefore focus on assessing whether legally defined excuses apply. Even in cases involving neurological conditions like brain tumors, the critical inquiry is the extent to which the condition impairs perception, decision-making, and, crucially, conscious control—defined as the ability to select goals, maintain them, and execute actions. It is not a question of whether an act was caused, but rather the nature of the causation. Can the act be attributed to the individual, or is it the result of a pathological disorder that exceeds their capacity for insight and control? This distinction is vital, as conflating causation with non-causation and legal responsibility is a common error, termed the "psycholegal error" by Stephen J. Morse. This understanding explains why the radical legal reforms advocated by some natural scientists since the 19th century have not materialized; criminal law is largely compatible with our understanding of human behavior’s causes.

Everyday Interactions:
The principles extend to everyday life. When someone spills juice on a prized sweater, our primary concern is not abstract free will, but rather intent and responsibility. Was it a deliberate act of malice, an accident, or an unavoidable mishap due to unforeseen circumstances? Did the person show remorse or offer compensation? These questions revolve around insight and conscious control: Did the individual understand their actions and were they in control of themselves?

Reconsidering Neuroscientific Experiments

Schleim proposes a reinterpretation of influential neuroscientific experiments, such as Benjamin Libet’s studies from the 1980s and their modern fMRI variations. These experiments, which typically asked participants to spontaneously move a hand or press a button and report the timing of their conscious decision, were often interpreted as evidence that unconscious brain processes precede and determine conscious choices.

However, Schleim argues that this interpretation overlooks crucial nuances. Libet himself did not deny the possibility of free will and emphasized that the measured "unconscious" neuronal activity, known as the "readiness potential," merely signifies the initiation of a movement. This initiation does not necessarily lead to the execution of the action. As Libet and others noted, there is a distinct process between the initiation and execution of a movement, and the nature of this process—whether conscious or unconscious—remains open to debate.

Furthermore, the experimental setup often involves conscious control. Participants are asked to consciously monitor their internal states to report the timing of their decisions. In fMRI studies, increased activation in brain regions associated with executive control and conscious processes, such as the prefrontal cortex and precuneus, has been observed. More recent research utilizing brain-computer interfaces has demonstrated that the execution of a movement can be consciously halted up to 200 milliseconds before it occurs, a finding consistent with Libet’s earlier predictions.

Therefore, Schleim suggests that the focus of the free will debate should shift from determinism to the possibilities and limitations of conscious control, aligning with the practical concerns of legal and everyday life. The real challenge to our concept of responsibility would arise if unconscious brain activations compelled us to act in ways we could not consciously override, which would indeed bring to mind the legal concept of pathological excuses.

Summary and Outlook

The discussion on free will, despite its long history and persistent arguments dating back to the 19th century, continues to generate significant attention. Physicist and philosopher Ernst Mach (1838-1916) suggested that questions that resist clear answers might be fundamentally misformulated. Schleim posits that the current free will debate is caught in a loop of arguing about unprovable determinism, while practical matters of law and society hinge on responsibility and guilt.

By shifting the focus from the abstract question of determinism to the tangible aspects of conscious control, Schleim believes we can move beyond this confusion. Improving scientific models of decision-making processes, grounded in empirical observation of conscious control, holds the key to advancing this critical discourse and its implications for how we understand ourselves and our societies. The insights gained from this reframed perspective are crucial for a more functional and practical understanding of human agency in both legal and social contexts.