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Sources · Free will

This house believes free will is an illusion.

Fact bank v1 · 12 cards

This is a philosophy motion, so the judge never rules either side's view true or false. These cards say what philosophers generally accept, and cover facts such as who argued what.

  1. FW-01

    “Libet's famous experiment found that brain activity for a movement starts before people feel they have decided to move.”

    What philosophers generally accept

    Confirmed: in Libet's 1983 study, a build-up of brain activity started at least several hundred milliseconds (a few tenths of a second) before the moment people said they first wanted to move.

    The study tested only 5 people. They made a simple movement whenever they felt like it, then said where a spot moving round a clock face was when they first felt the urge. When their moves felt fully spontaneous, the brain signal started about 350 milliseconds before that moment, on average. A 2011 study that recorded single brain cells in 12 people could predict a finger movement with more than 80% accuracy 700 milliseconds before people became aware of deciding. What these early signals mean is still argued over (see FW-04).

    “The onset of cerebral activity clearly preceded by at least several hundred milliseconds the reported time of conscious intention to act.”
    Brain (Oxford University Press), abstract via PubMed, US National Library of Medicine·Time of conscious intention to act in relation to onset of cerebral activity (readiness-potential): the unconscious initiation of a freely voluntary act (Brain, 1983)Government / parliament · 1 Sept 1983 ↗

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  2. FW-02

    “Brain scans can predict what you will choose up to 10 seconds before you know you have decided.”

    What philosophers generally accept

    A 2008 brain-scan study found signs of the outcome of a simple choice up to 10 seconds before people felt they had decided. But the predictions were far from certain. In a 2013 follow-up led by the same researchers, a choice could be read 4 seconds early, but only about 59% of the time, where pure guessing gets 50%.

    The 2008 study looked at simple movement choices. The 2013 study found the same kind of early signal for a free choice to add or subtract numbers. Being right about 59% of the time means the early brain activity only tilts the odds. It does not show that the choice was already fixed.

    “the outcome of a decision can be encoded in brain activity of prefrontal and parietal cortex up to 10 s before it enters awareness”
    Nature Neuroscience, abstract via PubMed, US National Library of Medicine·Unconscious determinants of free decisions in the human brain (Soon, Brass, Heinze and Haynes, Nature Neuroscience, 2008)Government / parliament · 13 Apr 2008 ↗

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  3. FW-03

    “The philosopher Spinoza argued that free will is an illusion.”

    What philosophers generally accept

    Confirmed: Spinoza, writing in the 1600s, held that every choice is caused by earlier causes. He wrote that the mind has no "absolute, or free, will".

    Spinoza thought people believe they are free because they know what they want, but not what causes their wants. In his words, people are "conscious of their actions and ignorant of the causes by which they are determined." He still thought people could become freer in a different sense: by understanding what drives them and living by reason instead of being pushed around by their feelings.

    “In the Mind there is no absolute, or free, will, but the Mind is determined to will this or that by a cause”
    Stanford Encyclopedia of Philosophy·Baruch Spinoza (Stanford Encyclopedia of Philosophy)Peer-reviewed research · 8 Nov 2023 ↗

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  4. FW-04

    “Libet's experiments proved that free will is an illusion.”

    What philosophers generally accept

    Libet's results did not prove this. His reading of the early brain signal has been heavily criticised, and after many later studies, scientists are still unsure what the signal means.

    One later study found the same kind of signal before people decided not to move, so it may not be a hidden decision to move (see FW-09). Another suggested that the exact moment of moving may mostly depend on random ups and downs in brain activity crossing a tipping point. Many philosophers, including many who doubt free will, reject the argument from these brain studies.

    “After extensive subsequent study, neuroscientists are uncertain what it signifies.”
    Stanford Encyclopedia of Philosophy·Free Will (Stanford Encyclopedia of Philosophy)Peer-reviewed research · 3 Nov 2022 ↗

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  5. FW-05

    “Most philosophers think free will is an illusion.”

    What philosophers generally accept

    In the 2009 PhilPapers survey of 931 philosophy professors at 99 leading departments, only 12.2% agreed with or leaned towards "no free will". 59.1% agreed with or leaned towards compatibilism, the view that free will can exist even if everything has a cause, and 13.7% towards libertarianism, the view that we have free will and the past does not fix our choices.

    A vote of experts does not settle who is right, but it shows that "no free will" is a minority view among philosophers. Another 14.9% gave other answers. Most of the departments surveyed were in the US and the UK.

    “Accept or lean toward: no free will 114 / 931 (12.2%)”
    PhilPapers·The PhilPapers Surveys: preliminary survey results (2009 survey, target faculty)Independent research institute · 1 Nov 2009 ↗

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  6. FW-06

    “Science has proved that everything, including every choice we make, was fixed by the past.”

    What philosophers generally accept

    Science has not proved this. Quantum physics, our best theory of tiny particles, can be read in ways that are fixed or not fixed, and experts do not agree which reading is right.

    Isaac Newton's laws once led many people to think the universe ran like clockwork. Quantum physics has made that picture doubtful at the smallest scales. The Stanford Encyclopedia of Philosophy says there is currently no good evidence that determinism is true, but it is not clearly false either. Some arguments against free will do not depend on determinism: they say we lack the kind of free will needed to deserve blame either way.

    “current science does not decisively support the idea that everything we do is pre-determined by the past”
    Stanford Encyclopedia of Philosophy·Free Will (Stanford Encyclopedia of Philosophy)Peer-reviewed research · 3 Nov 2022 ↗

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  7. FW-07

    “Even after the brain starts getting ready to move, people can still stop themselves.”

    What philosophers generally accept

    Confirmed: in a 2016 study, people could still cancel a movement after the early brain signal had started, as long as the stop signal came more than about 200 milliseconds (a fifth of a second) before the movement.

    People played a game against a computer that read their brain signals live and gave a stop signal when it detected they were getting ready to press a button. In the last 200 milliseconds or so it was too late to stop, which the researchers call a "point of no return". This shows the early signal does not lock in the action, but it does not settle where the decision to stop comes from.

    “Our data suggest that subjects can still veto a movement even after the onset of the RP.”
    Proceedings of the National Academy of Sciences, abstract via PubMed, US National Library of Medicine·The point of no return in vetoing self-initiated movements (Schultze-Kraft and others, PNAS, 2016)Government / parliament · 14 Dec 2015 ↗
  8. FW-08

    “Famous philosophers like David Hume argued that free will can exist even if everything we do has a cause.”

    What philosophers generally accept

    Confirmed: Hume is one of the best-known defenders of compatibilism, the view that freedom and moral responsibility fit with a world where everything has a cause.

    Writing in the 1700s, Hume said liberty is "a power of acting or not acting, according to the determinations of the will". In other words, being free means being able to do what you choose, not having no causes. Thomas Hobbes argued something similar. The Stanford Encyclopedia of Philosophy says this view was widely held by the major thinkers of that era, with Spinoza, Reid and Kant the clear exceptions.

    “It is widely accepted that David Hume’s contribution to the free will debate is one of the most influential statements of the “compatibilist” position”
    Stanford Encyclopedia of Philosophy·Hume on Free Will (Stanford Encyclopedia of Philosophy)Peer-reviewed research · 27 May 2020 ↗

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  9. FW-09

    “Libet's brain signal shows up just as much when people decide not to move, so it is not a hidden decision to move.”

    What philosophers generally accept

    A 2010 study found the brain signal was no stronger before a decision to move than before a decision not to move. The authors concluded that Libet's results do not show that movements start without our awareness. This is one study, and the debate about the signal goes on.

    The authors point out that Libet's argument depends on the signal being linked only to getting ready to move. A 2012 study offered another explanation: the build-up may partly come from random ups and downs in brain activity. The traditional view is that the signal reflects planning and preparing to move.

    “There was no evidence of stronger electrophysiological signs before a decision to move than before a decision not to move”
    Consciousness and Cognition, abstract via PubMed, US National Library of Medicine·Brain preparation before a voluntary action: evidence against unconscious movement initiation (Trevena and Miller, Consciousness and Cognition, 2010)Government / parliament · 6 Sept 2009 ↗

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  10. FW-10

    “Quantum physics shows the universe isn't fixed, so it proves we have free will.”

    What philosophers generally accept

    There is no good evidence for this. Experts do not agree on whether quantum physics means the universe is truly random, and there is little evidence either way that such randomness plays a part in our choices.

    One well-known physics calculation found that quantum effects in the brain fade in about a tenth of a trillionth of a second or less, while brain cells work over thousandths to tenths of a second. It concluded the brain behaves like an ordinary, non-quantum system. Philosophers also point out a problem: if a choice comes down to chance, like a roll of the dice, that looks more like luck than control.

    “Quantum theory is indeed very well confirmed. However, there is nothing approaching a consensus on how to interpret it.”
    Stanford Encyclopedia of Philosophy·Incompatibilist (Nondeterministic) Theories of Free Will (Stanford Encyclopedia of Philosophy)Peer-reviewed research · 18 Aug 2021 ↗

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  11. FW-11

    “Telling people free will is an illusion makes them cheat and behave worse.”

    What philosophers generally accept

    A famous 2008 study found this, but later attempts to repeat it mostly failed. A 2023 review of 145 experiments found that such messages do lower belief in free will, but found no evidence that they had any further effects.

    In the 2008 study, people who read that behaviour is caused by genes and surroundings cheated more on maths problems. A 2020 team tried to repeat it in five studies, the largest with 982 people, and mostly could not. 95 of the 145 experiments in the review had never been published, so studies that found nothing were counted too.

    “However, we could not find evidence for downstream consequences.”
    Personality and Social Psychology Review, abstract via PubMed, US National Library of Medicine·Manipulating belief in free will and its downstream consequences: a meta-analysis (Genschow and others, Personality and Social Psychology Review, 2023)Government / parliament · 8 Jun 2022 ↗

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  12. FW-12

    “Most ordinary people believe that if everything is determined, nobody can have free will.”

    What philosophers generally accept

    It depends on how you ask. In one well-known study, 66% of people said a woman in a fully determined universe still stole a necklace of her own free will. But when another study asked in general terms, 86% said no one in such a universe could be fully morally responsible.

    The 66% figure comes from Nahmias and colleagues (2006), and later repeat studies found lower numbers. In Nichols and Knobe's 2007 study of 41 people, those asked about a specific man who killed his family in a determined universe mostly blamed him: only 28% said he was not fully morally responsible. So people's gut feelings change with how concrete the example is.

    “Nahmias et al. report that 66% gave an affirmative response”
    Stanford Encyclopedia of Philosophy·Experimental Philosophy (Stanford Encyclopedia of Philosophy)Peer-reviewed research · 8 Apr 2026 ↗

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