excreationist

Taffy Lewis:

About non-zero probabilities...

tronvillain substituted non-zero probabilities in place of the words "nonzero probability".

Whatever is true of the class of nonzero probabilities should be true of all instances of this class.

e.g. the initial statement could be "mammals have four limbs". (hopefully that's true)

Then I could substitute "mammal" with a specific mammal.

e.g. "cats have four limbs"
"dogs have four limbs"

This is assuming they don't have birth defects or have had amputations, etc.

Also,

If something has no chance of happening, this means it has a probability of 0. If it is possible that it could happen, it has a probability greater than zero but less than or equal to one. If something is certain then it has a probability of 1.
All things have a probability of between 0 and 1.

Maybe the universe is truly random... maybe radioactive decay would happen differently if you used a time machine and repeated the event. In radiactive decay, each particle has a 50% (0.5) chance of decaying within the "half-life" time.

If the same thing happened each time you repeated the event by travelling to that point in time, then the universe would be deterministic (predetermined)... otherwise it would be based on probabilities which tronvillain calls "probabilistic determinism". People's decisions would still be at the mercy of their environment.

BTW, there is a doctrine called "compatibilism" that is relevant to this thread...

<a href="http://web.syr.edu/~jddraege/compatibilism.htm" target="_blank">http://web.syr.edu/~jddraege/compatibilism.htm</a>
"Compatibilism – Free will and determinism can be true together. All human actions are causally determined, but some behavior is caused in a way that is compatible with free will while other behavior is not."

<a href="http://www.geocities.com/Athens/Olympus/2178/compat2.html" target="_blank">http://www.geocities.com/Athens/Olympus/2178/compat2.html</a>
"What the compatibilist is saying is that free will – real free will – is compatible with determinism."

I don't think people have truly free will in a deterministic universe but they are somewhat free - more free than cats and worms at least.

Just to expand on what tronvillain was asking...

Do you have a version of "free will"? How does it arrive at its decisions? Maybe your system is part systematic part random. Well that is similar to determinism - since elementary particles are so numerous, large-scale systems (like our brains and environment) aren't completely predictable, like the weather.

Taffy Lewis

tronvillain:

Earlier, you said:

If, as you say, whether or not I should refrain from believing falsehoods "is dependent on whether or not you actually can refrain from believing falsehoods", then, given what you said in the first quote in this post, it follows that you don't think that I should accept your arguments.

In other words, if you don't reasonably believe that I can refrain from believing any particular falsehood (or falsehoods in general) then you can't reasonably believe on any given occassion that I should refrain from believing a falsehood. At least that would hold if one accepts your dependency claim.

So you can't claim that I should accept your arguments. But if you can't claim that I should then how can you claim that anyone should (including yourself)? Presumably you don't know whether others are determined either.

If by "apparent" you mean "it seems so but isn't" then of course this isn't incompatible with determinism. But the claim that one actually has alternative courses of action is certainly incompatible with determinism. If determinism is true then there cannot be any alternatives to what actually happens. That's what determinism means.

People make choices whether or not determinism is true. The question is are our choices determined by sufficient antecedent events or not. Determined choices and free choices are both choices.

The intuitions behind free will or free choice is that we seem to experience alternative courses of action such that which alternative occurs is one for which we are responsible. If our actions are determined then our experience of alternatives is illusory. Also, if our actions are due to chance (inside our central nervous systems or not) then it is hard to see how we can have the control necessary for responsibility. Therefore freely willed actions are a third way events occur in the world.

One might dismiss our experience of alternatives and control as illusory. However, if we are willing to ignore such a pervasive experience as choices then it is hard to see why we should trust the rest of our mind including our sensory and cognitive faculties.

[ June 13, 2002: Message edited by: Taffy Lewis ]</p>

Taffy Lewis

excreationist:

Thanks for your response.

Besides the events which have a probability of one and zero.

Actually, it could occur by chance that the same event continually occurs over and over no matter how many times you repeated it. So even if the same event repeated over and over the universe still might not be deterministic. Of course, that might be incredibly improbable.

Yes. Compatibilist understandings of free will are well known. bd-from-kg suggested a conditional analysis of "could have done otherwise" earlier in this thread. For example, G.E. Moore's "would...if..." analysis has been much debated. However, the question we have been pursuing is whether or not there is another type of free will that we have---incompatibilist freedom.

tronvillain

Taffy Lewis:
Yes, I can claim that you should accept my arguments. As I said before, I do not limit my usage of the word "should" to the sense used in your premises - I would say that you should accept my argument even if I were certain that you were incapable of doing so.

Of course, that is independent from my analysis of the argument:
Hello? Anybody home in there?

JB01

I don't know if this helps, but consider the following proposed definition of the word "should":

When I say someone "should" do X, I mean something like: Based on the information available to me at present, I am unable to determine whether he will choose action X or action Y (i.e., both appear to be possible), but I would prefer that he choose X. In other words, it isn't necessary that both X and ~X actually have nonzero probabilities for me to make the statement; it is only necessary that my best a priori estimate of each probability is nonzero.

If you accept my definition (or something with a similar structure but greater moral content), premise 2 is false, and the argument collapses.

Taffy Lewis

tronvillain:

What are some different senses of the word "should"? And which one do you believe the argument relies upon?

Taffy Lewis

JB01:

Is the appearance of alternative courses of action necessary in order for you to think that someone "should" do something? Are you saying that it should at least appear for someone to be free in order for you to suggest that they "should" do some action?

Suppose someone tells you that they want to go to a movie but they don't have a car. Now if they ask you "What should I do?" then isn't it the case that if you recommend some course of action then you believe they can follow it?

If you tell them "You should call so-and-so." or "You should take the bus." then isn't it the case that you must presuppose that they can do what you recommend?

Can anyone offer distinct definitions of "should" among which there is one which will avoid the argument and not be specifically formulated for the sole purpose of avoiding the argument. (In other words, it should be a sense of "should" that you would have had in mind even if this argument against determinism was never mentioned to you.)

JB01

Yes, it is. And I can make that presupposition even if determinism is true precisely because I don't know which course they will take (and, quite possibly, neither do they).

I don't think it's entirely fair to imply that my definition was constructed solely to avoid the argument. Assertions about what people "should" do are not statements of objective fact; they are subjective claims about the opinion of the person making the statement. As such, I think it's plausible that they might depend on that person's knowledge state.

Taffy Lewis

JB01:

Thanks for the response.

Consider this: "Based on the information available to me at present, I am unable to determine whether you will choose to take the bus or not (i.e., both appear to be possible), but I would prefer that you choose to take the bus."

Or this: "Based on the information available to me at present, I am unable to determine whether you will refrain from believing unjustified propositions or not (i.e., both appear to be possible), but I would prefer that you do not believe unjustified propositions."

Is this really what you would have in mind if you were suggesting to someone in these circumstances what they should do?

And does it really seem to be just a matter of opinion that "if a person wants to be rational they should refrain from believing unjustified propositions"?

It seems odd to me to refer to this as just a matter of opinion.

JB01

Clearly not. But I think we can distinguish between a "naked" should and one that appears as the logical consequence in an "If...then" clause. The former is the moral type, and its hidden premises are presumably my moral beliefs - which are matters of opinion. In your example, the "should" is objective, assuming we agree that believing unjustified propositions is irrational. Thanks for helping me get that straight.

Regarding your reformulation of my definition, what if I expressed it this way: "Neither of us knows in advance if you will always manage to refrain from believing unjustified propositions, but if you wish to behave rationally, you will prefer that you do so."

Does that make sense?