Robots & Rationality

By Tim Stratton

Determinists determined to defend determinism often counter the Freethinking Argument by proclaiming that computers seem to be rational and they do not possess libertarian free will. They state this is sufficient refutation of premise (3) of the Freethinking Argument, and therefore, the conclusions: free will exists, the soul exists, and naturalism is false, do not follow. This article exposes a major problem with this objection and demonstrates that the deductive conclusions of the Freethinking Argument remain unscathed.

Assumptions & Presuppositions

One problem with the “computer objection” is this: simply by stating that computers are, or robots of the future could be, rational in a deterministic universe *assumes* that the determinist making this claim has, at least briefly, transcended their deterministic environment and freely inferred the best explanation (the one we ought to reach) via the process of rationality to correctly conclude that computers are, in fact, rational agents.

Naturalistsic determinists presuppose they are rational humans while offering a computer as a completely determined rational agent. The question, however, is this: does rationality exist on naturalism? With the proper question in mind, the answer given must be an explanation as to how humans could be rational in a fully physical and causally determined world, not, “Well computers are rational!”

Again, if determinists happen to luckily be right about determinism, then they did not come to this conclusion based on rational deliberation by weighing competing views and then freely choosing to adopt the best explanation from the rules of reason via properly functioning cognitive faculties. No, given determinism, they were forced by chemistry and physics to hold their conclusion whether it is true or not. On naturalism there are no cognitive faculties functioning in a “proper” way according to a design plan which would allow one to freely think and infer what ought to be inferred. Simply offering a computer as a rational entity only sweeps the problem under the rug, but the problem remains as we are not discussing computers, but rather, the designers of computers.

If one is going to assert a certain view of the actual world, then the view offered should entail the ability of the proclaimer to make this rational inference in the same world. After all, one cannot rationally conclude a model of reality which destroys the very method he used to reach the conclusion. Alvin Plantinga notes the circularity involved by the naturalist:

“such a claim is pragmatically circular in that it alleges to give a reason for trusting our noetic equipment, but the reason is itself trustworthy only if those faculties are indeed trustworthy. If I have come to doubt my noetic equipment, I cannot give an argument using that equipment for I will rely on the very equipment in doubt.”[1]

Plantinga quotes Thomas Reed’s perceptive statement to support his case: “If you want to know whether [or not] a man tells the truth, the right way to proceed is not to ask him.” If you have reason to suspect a certain man is a liar, why should you believe this individual when he tells you that he is not a liar? Similarly, if we have reason to suspect we cannot freely think to infer the best explanation, why assume these specific thoughts (which are suspected of being unreliable) are reliable regarding computers?

Moreover, the naturalist who states that he freely thinks determinism is true is similar to one arguing that language does not exist, by using English to express that thought. The proposition itself counts as evidence against that view. If a naturalist is going to assume the ability to rationally argue that computers and robots can be rational in a deterministic and completely physical universe, they must first demonstrate they are not begging any questions by assuming they are rational to reach the conclusion that they are rational.

Until naturalists demonstrate exactly how a determined conclusion, which cannot be otherwise and is caused by nothing but physics and chemistry, can be rationally inferred and affirmed, then the rest of their argument has no teeth in its bite as it is incoherent and built upon unproven assumptions. As I always say, any argument based upon a logical fallacy is no argument at all. That is to say, even if a naturalist’s conclusion happens to be right, they have not offered any reason to think the conclusion is true, or any rational justification to think their causally determined thoughts are reliable or worth considering.


If all is ultimately determined by nature, then all thoughts — including what humans think about the rationality of computers — cannot be otherwise. We are simply left assuming that our thoughts (which we are not responsible for) regarding computers are good, the best, or true. We do not have a genuine ability to think otherwise or really consider competing hypotheses at all.

Bottom line: if naturalism is true, then there is no such thing as free will, and if there is no free will then there is no freethinking!

Stay reasonable (Philippians 4:5),

Tim Stratton


[1] William Lane Craig & JP Moreland note Alvin Plantinga’s claim in Philosophical Foundations for a Christian Worldview (page 107).

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5 replies
  1. Andy Ryan says:

    Philosopher Stephen Law called this the ‘hit on the head by a rock’ argument, with reference to Sye Ten Brugencate’s debating technique.

    My claim: Sye’s mind is addled and his thinking unreliable because he was hit on the head by a rock.

    Prove this is false Sye.

    Try to, and I will say – “But your “proof” presupposes your mind is not addled and you can recognise a proof when you see it. So it fails.”

    Ask me to prove my claim and I will say: “But prove to me your mind is not addled, then, Sye”. Which you won’t be able to, for the above reason. I might then add, with a flourish – “So you see, it’s proved by the impossibility of the contrary”.

    And of course I have a good explanation for why your brain is addled – you were hit by a rock.”

    I wouldn’t say that computers are ‘rational’, but I would argue that they can make reliable calculations.
    This is a counter to the argument that the supernatural is required for a brain to make reliable calculations.

    Tim says this argument begs the question, but it strikes me that he’s got it backwards. He is using the CONCLUSION of HIS argument – that brains cannot make reliable calculations, as an attempted defeater of COUNTERS to his argument.

    This is surely begging the question, similar to Stephen Law’s ‘hit by a rock’ satire, where any arguments that Sye wasn’t hit on the head by a rock are dismissed on the basis that they’re coming from someone who Law argues was hit on the head by a rock.

    “Until naturalists demonstrate exactly how a determined conclusion, which cannot be otherwise and is caused by nothing but physics and chemistry, can be rationally inferred and affirmed, then the rest of their argument has no teeth in its bite as it is incoherent and built upon unproven assumptions.”

    You’ve not shown how the supernatural would make any difference to this. Adding magical parts to a causal chain doesn’t stop it being a causal chain, and the alternative to a causal chain is not free will but chaos.

    Further, if God knows every single choice you will ever make then arguably ALL of your choices ‘cannot be otherwise’ in any meaningful sense. Quite literally, YOU COULD NOT CHOOSE DIFFERENTLY.

  2. Andy Ryan says:

    KR argues it better than I do on other thread here, “Are Humans Sophisticated Carbon-Based Machines?”:

    KR: “As a determinist I don’t think there is any such thing, the whole concept seems logically incoherent. I’ve laid out the argument for this in other threads on this site but here it comes again: to qualify as a free will choice (I’m talking about libertarian free will), this choice must have a reason. A choice made without a reason lacks intentionality and deliberation and cannot be the expression of the agent’s will – it’s basically a random occurrence. Moreover, the reason for the choice must be under the control of the agent – otherwise the choice is determined and not free.

    This means that the reason for a free will choice must also be a choice, which of course also needs a reason, a s o, a s o. The only way the agent can get out of this regress with his free will intact is through an action that is not by choice but still under the agent’s control. In other words, it would have to be simultaneously involuntary and voluntary – an obvious contradiction.”

    Note that this argument applies in both a theistic or materialistic atheist universe – introducing the supernatural makes no difference.

  3. Luke says:

    Let me start with 3 simple questions for Tim:

    1. Do you believe that there is a fact of the matter to the question: are computers capable of rationality (for any specific definition of rationality)?

    2. Do you agree that if somputers are capable of rationality, then persons in a deterministic universe would also be capable of rationality?

    3. Can you demontrate that a “soul/immaterial thinking thing” is free from outside interference from any persons who exist (at least in part) in the same immaterial realm?

    Okay, on to my comment: It’s quite likely that I have completely misunderstood this post, because I have no idea what the problem is supposed to be.

    Everyone involved believes that everyone else is able to ratioanlly analyze the question: “are computers capable of rationality?”.

    Tim thinks everyone can analyze this question, because he believes everyone has the free will, and that free will is needed for rationality.

    The determinist in the argument believes everyone can analyze this question, because he or she believes that rationality is possible with determinism.

    So what’s the problem?

    Reading this made me think of the legal concept of standing in a court case. Here is how I see what Tim is saying:

    Judge: Petitioner, do you believe you have standing in this case?
    Petitioner: Yes, your honor.
    Judge: Responder, do you believe the Petitioner has standing in this case?
    Petitioner: Yes, your honor.
    Judge: Then the court will be able to rule in this case. Let’s move on to the argu…
    Respondent (interrupting): Wait judge! There is a hypothetical person that has part of the petitioner’s beliefs (everything is determined) and part of my beliefs (rationality cannot exist on determinism), and that made up, hypothetical person would believe that the petitioner does not have standing.

    That’s what Tim is saying, not that he believes that the determinist is incapable of rationally approaching the problem, nor that the determinist believes he is incapable of rationally approaching the problem, but that a hypothetical person with a mix of views from the determinist and from Tim would think the determinist incapable of rationality.

    Tim gives support for his argument by saying: ” If you have reason to suspect a certain man is a liar, why should you believe this individual when he tells you that he is not a liar?”

    Yet this badly misunderstands and misrepresents Tim’s case.

    Let’s make this reflect our argument more closely, then analyze it:

    If you suspect a certain man is incapable of rationality, why should you believe this individual when he tells you he is rational?

    But Tim does not suspect this person nor anyone else of being incapable of rationality!

    Tim believes we can all approach rationally!

    In other words: Tim doesn’t suspect the man is a liar at all! In fact Tim is adamant that the man is not a liar! (Or in our case, Tim is adamant the man has free will, and can be rational.)

    (Tim suspects that if the man took on parts, but only parts, of Tim’s beliefs, the man would think himself a liar.)

    I still harbor hope that Tim will one day answer my questions regarding his argument in the “Can Evolution Account for Rationality” thread.



    • Andy Ryan says:

      Yes, Tim’s argument here is disingenuous and plain doesn’t work.

      Why doesn’t Tim just come out and say whether HE thinks computers can make correct calculations despite not having free will? Simple yes or no. Because that’s what it comes down to here – what does HE believe here?

      If Tim thinks computers can can then surely he must concede this is a valid counter to the argument that free will is necessary for correct or at least reliable calculations. And presumably he DOES trust computers in this way or he wouldn’t be using them to spread his apologetics arguments. I mean, why use them if they’re that unreliable?

      And if he believes computers CAN make reliable calculations, and thus accepts that free will isn’t required for rational decision-making, then he must accept that even by his own logic atheists can too, and are justified by their own worldview to say they can too, and thus can point to computers to refute his argument.

      To cap it all, Tim closes off telling US to be reasonable!

  4. KR says:

    Tim writes: “Until naturalists demonstrate exactly how a determined conclusion, which cannot be otherwise and is caused by nothing but physics and chemistry, can be rationally inferred and affirmed, then the rest of their argument has no teeth in its bite as it is incoherent and built upon unproven assumptions.”

    I believe this has already been done. I agree with Alvin Plantinga when he points out that if the ToE is correct, then our brains have evolved to provide a survival benefit, not to produce true beliefs. I don’t think the two can be completely divorced but neither can they be assumed to always be connected. Where I disagree with Plantinga is in his conclusion that this leaves the naturalist without any means of knowing if her beliefs are true.

    We’ve known for about half a millennium of a way to do just that: the scientific method. I believe Tim is misrepresenting naturalistic determinists when he claims that they “presuppose they are rational humans”. I don’t presuppose any such thing – quite on the contrary, I have every reason to be suspicious of my own reasoning – especially when I’m operating with limited data.

    This is the very reason I’m an empiricist. It’s the fact that the scientific method acknowledges the fallibility of human reasoning that has made it so successful. By breaking down a problem into simple questions that can be unambiguously answered with “yes” or “no” by objective observations, we have gone a long way towards eliminating our minds (with all their cognitive biases, wishful thinking and misconceptions) as a source of error.

    We’re not using our reasoning to test our reasoning, we’re using our reasoning to make predictions that can be confirmed or falsified without using our reasoning – just by making an objective observation. This doesn’t give us absolute truths but it brings us ever closer to truth by falsifying our bad ideas.

    It’s always good to nail down definitions in discussions like this because I think we may actually mean different things when we talk about rationality and knowledge. For me, rationality means trying to align our beliefs with observed reality and knowledge is what we have have verified to be true. I don’t see why rationality defined this way would require free will (as has already been noted I don’t believe there is any such thing as free will in the libertarian sense).

    Before I get accused of “scientism”, I’d like to make clear that I don’t make the claim that empirical verification is the only way to acquire knowledge. I’m just not aware of any other way of verifying our ideas – and verification seems to be at the heart of “knowing”.


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