You make a good point. All I get from the argument is that determinism is not rationally justified if determinism is true. This doesn't (obviously, to me) mean that determinism is false. Now his point may simply be that it is not rationally justified, and so (as beings invested in being rational) we ought not accept it as true.

what is the standard for a belief to be rationally justified anyway?

It sounds like that word "rational" needs to be defined before we even talk about whether determinism is self refuting.

It sounds like that word "rational" needs to be defined before we even talk about whether determinism is self refuting. — Walter Pound

Indeed. And defining rationality pretty soon becomes philosophy's project. To determine the rational is in some sense to determine everything else. If I grant your method authority, then you do indeed give the last word on reality. Note that objectivity is authoritative for philosophy in the grand sense (for those who assume that reality can and should be determined rationally.)

*There are anti-philosophers who deny rationality/objectivity, but this is problematic if they ask to be taken as authorities.

I have to go to work, so I might respond in more depth later, but doesn't it appear that a lot of these types of arguments are circular?

"Rationality and determinism are incompatible. Why? Because you require free will in order to be rational. Why? Because if you lack free will, all you choices a determined i.e. determinism is true."

It appears that the conclusion is inserted into the premises of the argument.

yes, that argument is silly. The guy was determined to make it though, so here it is

Determinism does seem problematic for knowledge.

Do I believe 2+2=4 simply because my brain is in a certain state? That seems untrue because I can reflect on the logic behind 2+2=4 and am not simply forced to believe it.

To me reevaluating and testing beliefs is the reverse of determinism.

I think Eccles is saying that to deny freewill due to determinism is presupposing a choice to make the denial, hence contradictory, therefore irrational. Or else denial is but an automated response genetically determined, therefore cannot be considered rational due to being prejudiced. So by this way, determinism refutes itself if it wants to be considered a rational theory.

Churchland's objection to this is that it doesn't follow that, even if determinism is true, we do not reason rationally and I tend to agree. If a person is asked for the quantity of marbles in a jar and reasons via calculus but is out by, say, five marbles from the actual quantity, I don't think it is necessarily so that this person's reasoning was irrational or non-rational. The most that can be said is that the question determined an answer of quantity, not quality of answer.

As far as Eccles's contribution to the debate, the passage that Churchland quotes is the extent of that particular argument - not very illuminating, to be sure. Dr. Eccles, a Nobel-winning brain scientist and an old-fashioned Cartesian dualist, devotes the rest of the article to a detailed discussion of the neurophysiology of the brain and his thoughts about mind-brain interaction.

The argument that Popper makes in The Self and Its Brain (1973)* is that by committing to determinism you forfeit any claim to rationality; in particular, you cannot support your belief in determinism by a rational argument. Thus, determinism is self-undermining (not self-refuting). This argument does not provide you a reason to think that determinism is false. It only purports to show that you cannot possibly have a rational reason for believing determinism.

* The book was written in collaboration with Eccles, but they wrote two of the three parts independently, and Churchland's references in that book are to Popper's part.

Note that by determinism Popper means both causal determinism (the idea that "physical theory, together with the initial conditions prevalent at some given moment, completely determine the state of the physical universe at any other moment"), and more generally, "mechanical determinism," materialism, or physicalism - all of these terms are used interchangeably. His main challenge is to the idea of the causal closure of the physical world, or "World 1":

First, there is the physical world - the universe of physical entities...; this I will call "World 1". Second, there is the world of mental states, including states of consciousness and psychological dispositions and unconscious states; this I will call "World 2". But there is also a third such world, the world of the contents of thought, and, indeed, of the products of the human mind [such as stories, explanatory myths, tools, scientific theories (whether true or false), scientific problems, social institutions, and works of art]; this I will call "World 3"...

One of my main theses is that World 3 objects can be real...: not only in their World 1 materializations or embodiments, but also in their World 3 aspects. As World 3 objects, they may induce men to produce other World 3 objects and, thereby, to act on World 1; and interaction with World 1 - even indirect interaction - I regard as a decisive argument for calling a thing real. — The Self and Its Brain

Popper argues that all of these "worlds" exist and causally interact with each other. (And even within each world there are still more worlds, or layers, that likewise exhibit both upwards and downwards causation.) World 2 emerged from World 1 in the course of biological evolution, and World 3 emerged from the other two. But this order of emergence does not reflect the hierarchy of causal relationships between the worlds, because once they emerge, they begin to strongly interact with each other in every direction.

As for the argument that Churchland criticizes, it proceeds from Popper's rejection of epiphenomenalism: the idea that the mental is causally inert and does not interact with the physical world - which to him means the same thing as to say that the mental is not real. And this leads him to conclude that "if epiphenomenalism is true, we cannot take seriously as a reason or argument whatever is said in its support.".

The proof of this thesis is offered in the form of a lengthy dialogue between a Physicalist and an Interactionist, but my impression is that the idea of self-defeat, declared beforehand, does not come through clearly in that dialogue. Popper once again endeavors to defend the reality and indispensability of his World 3 - the world of ideas - and once he is satisfied that he has thrashed his imaginary opponent on that point, he declares victory.

I suppose a sketch of the argument would look something like this:

1. If the physical world is causally closed (this thesis Popper variously labels as materialism, physicalism or determinism), then it follows that the world of ideas is causally inert. (Some alternatives, such as the identity thesis, are rejected in separate arguments.)

2. Take any proposition, such as 1 + 1 = 2, or indeed the proposition that affirms the truth of physicalism. To what does it owe its truth? Both the proposition and any arguments in support of its truth are abstract ideas. But the physicalist only has the physical world at her disposal to make the argument. Nor can the abstract be reduced to the physical. Thus it follows that the physicalist cannot rationally support her own position.

More later.

Great post. I like the mention of World 3. Have you looked into Husserl? Whatever 'meaning' is, it is largely objective (unbiased) and effective in whatever 'nonmeaning' is. It also occurs to me that the 'physical' is no more clearly specified than the nature of language allows. The specification of non-language or non-meaning happens within language or meaning.

by committing to determinism you forfeit any claim to rationality; in particular, you cannot support your belief in determinism by a rational argument. Thus, determinism is self-undermining (not self-refuting). — SophistiCat

Indeed, that makes sense to me.

Have you ever heard the claim that determinism is "self-refuting" because if one is determined to believe in determinism that somehow means that we do not rationally believe in determinism? — Walter Pound

(Let me start by noting that I'm not a determinist, so my comments below are not sourced in wanting to support determinism:)

I haven't heard that claim before (or I don't recall it at least--I have a crappy memory), but it's not a good argument.

First off, whether determinism is true would have jackshit to do with whether anyone rationally believes determinism is true. Anything that anyone believes (rational or otherwise) isn't going to have any impact at all on whether determinism is true or not.

Further, all someone would have to say is that if we can't rationally believe in something just in case determinism is true (which this argument, sans other details, has to be suggesting, otherwise it's a non-sequitur), then if determinism is true, we don't rationally believe in anything (including, of course, Sir Eccles' and others' belief that determinism is false) . . . and so what? It's not as if there's a requirement in this case that we rationally believe anything.


This comment I do not understand as written, by the way: "This denial . . . presupposes free will for the deliberately chosen response in making that denial." I suppose he was just suggesting someone essentially saying, "I chose that 'determinism is true' of my own free will"? No one would say that.

Maybe Sir Eccles was simply saying that he doesn't consider anything a rational argument if one didn't freely choose to believe it, and he requires a rational argument to be persuaded that P, so he cannot be persuaded that determinism is true. Aside from that fact that that would be question-begging, he's also assuming that anyone's goal would be to persuade him that determinism is true. I don't know why anyone should care if he believes that determinism is true. (Especially not when he's set up a impossible, question-begging requirement to be persuaded.)

Have you looked into Husserl? — sign

No, I stick with analytics; continentals make my cat-brain hurt :razz: Although the clarity of analytic philosophers can be deceptive (when it is not trivial). For example, I still don't have any clear idea of how "interactionism" is supposed to work: exactly how those worlds and levels are supposed to be affecting each other? Popper doesn't really explain.

1. If the physical world is causally closed (this thesis Popper variously labels as materialism, physicalism or determinism), then it follows that the world of ideas is causally inert. (Some alternatives, such as the identity thesis, are rejected in separate arguments.)

2. Take any proposition, such as 1 + 1 = 2, or indeed the proposition that affirms the truth of physicalism. To what does it owe its truth? Both the proposition and any arguments in support of its truth are abstract ideas. But the physicalist only has the physical world at her disposal to make the argument. Nor can the abstract be reduced to the physical. Thus it follows that the physicalist cannot rationally support her own position. — SophistiCat

Man, I don't remember any of that, although I can't even remember if I read that book now.

At any rate, that's problematic that Popper is conflating materialism/physicalism and determinism (in my opinion as a physicalist who isn't a determinist).

In my view, the abstract is easily "reduced" to the physical.

Arguments to the effect that determinism (and/or materialism/naturalism/physicalism) is self-defeating* abound. In The Self and Its Brain Popper cites biologist J. B. S. Haldane's argument (later retracted) from 1932: "...if materialism is true, it seems to me that we cannot know that it is true. If my opinions are the result of the chemical processes going on in my brain, they are determined by the laws of chemistry, not of logic." He traces the argument even further back, all the way to Epicurus: "He who says that all things happen of necessity cannot criticize another who says that not all things happen of necessity. For he has to admit that his saying also happened of necessity." **

* Either in the sense that it is self-contradictory, i.e. it implies its own falsity, or more commonly, in the sense that it undermines rationality, and therefore cannot be rationally justified, even if true.

** Popper acknowledges one (rather week) objection to such arguments, which he addresses, but it is not the objection that Churchland makes, contrary to what he says in his reply to her (Is Determinism Self-Refuting, 1983).

Here is C. S. Lewis, writing in 1947:

Supposing there was no intelligence behind the universe, no creative mind. In that case, nobody designed my brain for the purpose of thinking. It is merely that when the atoms inside my skull happen, for physical or chemical reasons, to arrange themselves in a certain way, this gives me, as a by-product, the sensation I call thought. But, if so, how can I trust my own thinking to be true? It's like upsetting a milk jug and hoping that the way it splashes itself will give you a map of London. But if I can't trust my own thinking, of course I can't trust the arguments leading to Atheism, and therefore have no reason to be an Atheist, or anything else. Unless I believe in God, I cannot believe in thought: so I can never use thought to disbelieve in God. — Lewis

James Jordan in Determinism's Dilemma (1969) identifies and critiques a version of the argument in Kant, as well as in a few more recent writers. Here is his own emendation:

Suppose we are asked to accept the proposition that all our rational assessments have sufficient - not just necessary - causal conditions. In order to show that we ought to believe this, someone would need to produce evidence which is seen to conform to criteria of reasonable trustworthiness and which is recognized to confer, by virtue of some principle of deductive or probable inference, certainty or sufficient probability upon it. But if the proposition is true, this could never happen, for it implies that whether anyone believes it and what he considers trustworthy evidence and acceptable principles of inference are determined altogether by conditions that have no assured congruence with the proposition's own merits or with criteria of sound argumentation whose validity consists of more than that we accept them. Whether we believe the proposition and what considerations we undertake before making a decision depend simply on sufficient and necessary causal conditions that logically need not be, and quite probably are not, relevant to the issues involved in assessing propositions for truth and arguments for validity. If our rational assessments are conditioned solely by factors whose exhaustive statement would omit mention of the recognized accordance of our deliberations with criteria of trustworthy evidence and correct inference, then the recognition of the relevance of these criteria is either inefficacious or absent. Of course, one still might occasionally believe what is true, but this would always be the out come of happy circumstances, never of reasoned investigation. And if this is true of our rational assessment of any argument, it is true of our attempts to determine the strengths and weaknesses of any argument for the proposition in question. If the latter is true, any argument for it is self-defeating, for it entails that no argument can be known to be sound. — Jordan

Alvin Plantinga's Evolutionary Argument Against Naturalism (EAAN) is of the same nature. It takes on the more specific claim that our cognitive faculties arose by way of natural evolution, with no supernatural guidance, but its thrust is basically the same. A similar argument was given earlier by William James. Having been revived by Plantinga, EAAN has spawned its own body of literature.

I have come across dozens more papers discussing the thesis, often in the context of the freedom of will (by those who are impressed by incompatibilist arguments).

In The Self and Its Brain Popper cites biologist J. B. S. Haldane's argument (later retracted) from 1932: "...if materialism is true, it seems to me that we cannot know that it is true. If my opinions are the result of the chemical processes going on in my brain, they are determined by the laws of chemistry, not of logic." He traces the argument even further back, all the way to Epicurus: "He who says that all things happen of necessity cannot criticize another who says that not all things happen of necessity. For he has to admit that his saying also happened of necessity." ** — SophistiCat

Why isn't it obvious to people that those are horrible arguments, though?

First off, materialism doesn't entail determinism. Secondly, Haldane is just assuming that if determinism is true, then (a) knowledge isn't possible, and (b) logic isn't possible. We would at least need some sort of plausible argument for (a) and (b).

And re the Epicurus quote, obviously in that case (if determinism is true) "criticizing another who says that not all things happen of necessity" also happened of necessity. So rather that it being the case that the first guy cannot criticize the second, it would rather be that the first guy cannot NOT criticize the second.

There are similar problems with the other arguments, too, although at least Jordan's is not so conspicuously stupid.

Such a huge percentage of arguments in philosophy (not just these, not just this topic, but across the entire field in general) strike me as ridiculously bad to an extent where they suggest that the originator is rather dim-witted (albeit with a large or at least esoteric vocabulary). It's really disappointing.

Not that I'm a determinist, by the way, I'm not. But I'm not going to endorse a bad argument just because the conclusion is something I agree with. We could say "If free, rational thought guides these arguments, then that's maybe one of the better endorsements that desiring alternatives could have." ;-)

if determinism is true, then (a) knowledge isn't possible — Terrapin Station

Okay, so is his argument hiding a hidden premise? Is it the case that he believes that for knowledge to be possible that one must be able to have libertarian free will?

Yes. Otherwise his comment/argument wouldn't make sense. If determinism implies that we can't know x, then one has to be saying that freedom is necessary to know x.

At any rate, that's problematic that Popper is conflating materialism/physicalism and determinism (in my opinion as a physicalist who isn't a determinist). — Terrapin Station

This is not an unusual use of the term determinism - at least it was not at that time. Nowadays determinism is most often taken to mean Laplacean causal or nomological determinism, but in the context of the freedom of will and related topics, determinism was sometimes taken to mean something else. Boyle, Grisez & Tollefsen have a nice discussion of it in Determinism, freedom, and self-referential arguments (1972). They give the following definition:

[N]o special interpretive model beyond the interpretive models used to account for natural events and processes is needed to account for the initiation of human actions; an additional interpretive model used to account for the initiation of actions is a needless proliferation of explanatory machinery. Reformulated in terms of our previous description of the ordinary man's understanding of his actions, determinism implies that there is no warrant for a naively realistic interpretation of the experience of choice among alternatives. Determinism, in the sense in which we are concerned with it here, must exclude any interpretation of that experience which involves a claim that there are really open possibilities among which it is up to the agent alone to choose. — Boyle, Grisez & Tollefsen

So determinism is effectively opposed to libertarianism: "explanations of human actions exhibit the appropriate inferential and nomological pattern of explanations found in physical and biological sciences," as opposed to "explanations of action form a unique type of explanation with special logical and methodological requirements distinct from those of explanations in natural science." (Richard Brandt and Jaegwon Kim, "Wants as Explanations of Actions," 1963).

As should be clear, determinism in this sense is compatible with causal indeterminism.

You are right in that Popper does not make such a clear distinction - in fact, he talks explicitly about Laplacean determinism in places. But I suspect that his thinking was motivated more by the other sense, that of explanatory determinism. Nevertheless, both he and Eccles end up betting on causal indeterminism on their quest to escape explanatory determinism - which I think occasions confusion.

To my mind, determinism does not express the factual content of a proposition, rather it expresses our intended use of a proposition. We don't discover physical laws that were already there in our absence, rather our physical laws express our intended cultural responses to our observations, similar to our legal laws.

To see this, suppose that we were trying to teach Physics to an unruly student who refused to abide by our experimental physics conventions in his application of the equations. Since we can only provide him with a finite list of commands, he can always find a way to abide by our stated instructions and yet violate our intentions to produce nonsensical and lawless results.

Our Physical laws are therefore only meaningful relative to our obedience to the experimental conventions that we use to confirm them. Hence they are partially representative of our choice to conform to physics culture.

If determinism is meant to be the the future being caused by the past then yes it is self refuting. We can never know the future, certain elements we can predict with varying degrees of accuracy but the future is not beholden on the past. The past has no 'power' we could ever know over the future just as the cause has no power we could ever know over the effect.

You seem to be responding to one word in the title of the thread and nothing else besides.

That's not determinism being self-refuting, i.e. denying or undermining itself through its own entailments - that's just you denying determinism. Not the same thing, and not what the topic is about.

"this denial either presupposes free will for the deliberately chosen response in making that denial, which is a contradiction, or else it is merely the automatic response of a nervous system built by genetic coding and molded by conditioning"

Right. So a determinist cannot interpret his opponent as asserting a contrary epistemological position. Therefore the determinist cannot interpret his own position as making an epistemological claim.



My view is that any assertion of a necessary consequence is an active imperative as opposed to a passive description of an objective matter of fact. Therefore i agree with the above argument that determinism isn't an epistemological position.

this denial either presupposes free will for the deliberately chosen response in making that denial, which is a contradiction, or else it is merely the automatic response of a nervous system built by genetic coding and molded by conditioning — Eccles

Right. So a determinist cannot interpret his opponent as asserting a contrary epistemological position. — sime

I can't see how you are getting this from the quoted snippet. I think you are just reading into it your own thoughts (which I don't claim to understand).

By his very belief in universal determinism, the determinist, if he is consistent, cannot interpret his opponent's sentence " I possess free will" to be an actual claim to possess an objective property. This is because if universal determinism is true then the only objective meaning the determinist can ascribe in his opponent's sentences are the physical causes that precipitated them. Therefore the determinist must understand his opponent's sentences to be trivially and necessarily correct in an epistemological sense whatever those sentences are, and to be 'wrongable' only in the conventional sense of disagreeing with the linguistic convention adopted by the determinist.

This paradoxically implies that the thesis of universal determinism makes no substantial objective claims either, by failure to oppose a substantial counter-thesis.

To my understanding, our practical usage of the verb "to determine" which always relates a 'determiner' and a thing being determined, points to the natural way of dissolving the problem of free will.

By his very belief in universal determinism, the determinist, if he is consistent, cannot interpret his opponent's sentence " I possess free will" to be an actual claim to possess an objective property. This is because if universal determinism is true then the only objective meaning the determinist can ascribe in his opponent's sentences are the physical causes that precipitated them. Therefore the determinist must understand his opponent's sentences to be trivially and necessarily correct in an epistemological sense whatever those sentences are, and to be 'wrongable' only in the conventional sense of disagreeing with the linguistic convention adopted by the determinist. — sime

This sounds somewhat like Popper's argument that says that physicalist (let's call it that to avoid confusion) ontology is too impoverished. But a physicalist need not limit herself to just the "objective" language of physical causes. At least I haven't yet seen a persuasive argument to that effect.

"Rationality and determinism are incompatible. Why? Because you require free will in order to be rational. Why? Because if you lack free will, all you choices a determined i.e. determinism is true."

It appears that the conclusion is inserted into the premises of the argument. — Chany

A computer can be programmed to make rational decisions without giving it the property of free will, so I'm not convinced the conclusion is in the premises. Then it seems to boil down to whether it is the rationality encoded in the software or the atoms in the hardware that are causing the decision.

There seems to be different conceptions of determinism at play: one based on the closure of physics, the other seems to admit other forces such as reason. I don't understand the latter conception.

I think the problem lies in the premise that if one responds instinctively, one is responding irrationally. Animals are not irrational. Determinism implies that they respond to stimuli just as they were designed and learned to do.

I think that Popper and Eccles really mean the sort of material determinism that takes the universe from one state to the next. If you admit the causal power of "animals" and "design" you are already stepping outside material determinism, into a situation where abstractions are causal. I think the two conceptions are distinct, and this could be the cause of some confusion.

I think that Popper and Eccles really mean the sort of material determinism that takes the universe from one state to the next. If you admit the causal power of "animals" and "design" you are already stepping outside material determinism, into a situation where abstractions are causal. I think the two conceptions are distinct, and this could be the cause of some confusion. — Inis

No. The confusion arises out of making them distinct. Abstractions are causal. They cause us to behave in certain ways when they are in or mind. How did those words, "animals" and "design" get on the screen in your post if the abstractions, "animals" and "design" aren't causal?

It makes no sense distinguish between, "material" or "abstractions" when they both are causal. That is why I didn't use those terms in my explanation. They are unnecessary and cause more problems than they solve. Dualism is a false dichotomy. Monism is the truth.

What laws do abstractions obey? We know the material is bound by the laws of physics, so presumably abstractions have similar constraints. What are they?

I already asked you this question. You're asking me how they work, when I asked you the same question. How did the words, "animals" and "design" get on this screen in your post? If you are the one claiming that they are separate, then what are the rules for how abstractions behave and how are those any different from how matter behaves? If I claim that abstractions and matter are the same thing, then I'm not claiming that they obey different laws than "matter". You are and so it is up to you to explain their differences.