my psych teacher talked about how nothing can be predicted,
true: one cant make a 100% correct prediction based on past events, and even 100 is not possible.
am i “confused” or is my teacher wrong
It seems to me that your teacher believes in free will. That to some extent, rational beings have a sub conscience that allows them to make decisions based on intuition and not on facts and experience.
For example, if you walk into the kitchen on a hot summer day, you have the choice between hot tea from the stove, or iced tea from the fridge. From experience, the iced tea is the 100% correct choice, it is even the most proboble from a rational standpoint, but, based on your “mood”, there is a probobility that you would choose the hot tea.
But, on the other hand. If you were to take a hard deterministic standpoint, you could say. If a sufficiently knowledgeable being were present at the beggining of the universe and observed all events that would ever effect you in any way. He would be able to judge whether or not you would drink the hot tea or not with 100% accuracy.
So, it all depends on your view of free will. Do you believe that their is an exact science to behavior, or a loose science. Given all necessary information, could we predict what a person in that hot kitchen would do for certain? Or could all of us fool that all knowledgeable being that thinks it knows exactly what we will do.
P.S. - This reminds me of the end of “Breakfast of Champions”
That nothing can be predicted completely accurately is a sad scientific fact, so your teacher is right regardless of deterministic questions.
100% true predictions CAN made if we use laws of nature:
It’s a factual truth that if you boil sulfur, it will reach boiling point at exactly 444.6° celsius
It’s a factual truth that pure copper will conduct electricity
what’s science without facts?
We can’t make those predictions without a complete model of the universe! What if the universe collapses before the copper conducts electricity? Improbable, but not impossible.
Not necessarily. Non-determinism does not entail free will. I don’t think this teacher even had free will in mind in that statement.
You’re teacher is correct. We can all make educated conjectures to one degree of accuracy or another, but it should be obvious to all that no one can ever predict anything with 100% accuracy.
From Roderick M. Chisholm - “Human Freedom and the Self”
[i]We may distinguish between what we might call the ‘Hobbist’ approach and what might be called the ‘Kantian’ approach…According to Hobbism, if we know, of some man, what his beliefs and desires happen to be and how strong they are, if we know what he feels certain of, what he desires more than anything else, and if we know the state of his body and what stimuli he is being subjected to, then we may deduce, logically, just what it is that he will do - or, more accurately, just what it is he will try, set out, or undertake to do.
But according to the Kantian approach to our program…there is no such logical connection between wanting and doing, nor need there even be a causal connectio. No set of statements about a man’s desires, beliefs and stimulus situation at any time implies any statement telling us what the man will try, set out, or undertake to do at that time. As Reid put it, though we may ‘reason from men’s motives to their actions, and in many cases with great probability’, we can never do so ‘with absolute certainty’.[/i]
This view seems to mirror the physical explanation for an indeterministic universe via quantum physics.
Presumably a predictions truth or falsity can only be measured after the event has occured. A prediction, by its very definition, is neither true nor false and can only later be correct or incorrect.
It’s true that up until this moment in time, sulfur has always boiled at exactly 444.6 celsius, but that is merely inductive reasoning to the laws of nature. Hume spent a lot of time explaining how we have no reason to suppose that laws of nature will hold forever because it is not necessary that the future will imitate the past. For sure we can be pragmatic about things and be sure beyond reasonable doubt that this law will hold true, but we can never be certain, which is what this debate is about.
- ben
Laws of nature, unlike physical laws, are true for every time and every place in the universe. The boiling point of sulfur is a factual and universal truth.
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Laws of nature, unlike physical laws, are true for every time and every place in the universe. The boiling point of sulfur is a factual and universal truth.
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Yeah, I guess I’d have to agree with that, too.
but you’d have to know those laws, which we don’t,
but even then, heisenbergh and chaos theory showed us the impossibility of prodicting the future 
willem
Hang on, where is your proof of this? How do you know that tomorrow all the sulfur in the world will not start boiling at a different temperature? You can make a pretty good guess, I agree, but you can’t know for certain that it will. That is my point. I’d be interested to see your proof that laws of nature will be eternal for all time since there is only inductive reasoning which is not 100% certainty.
Russell uses the example of a chicken who is fed every day of his life by a farmer. By the same reasoning the chicken believes that tomorrow he will also get fed by the farmer. One day, the farmer rings his neck. So much for the chicken’s reasoning.
I’m afraid that just asserting your belief in the eternity of laws of nature will not suffice as proof.
- ben
You guys missed Ben’s point.
How do you know any physical law of nature holds for “all times and all places”?
Science is based on observations, ie things that happened and were in the past. Whatever law so induced holds, strictly speaking, only for all the past events, from which a sampling of observations were made. There is nothing in the scientific method to compel you to conclude that the law so induced will hold for the next second and for places you have never been.
Well yes we can conjecture that it may hold, and actually conduct tests to see that it holds; and we observed it does hold, and so we assume that it will hold for the foreseeable future.
However the basis for the law being true tomorrow is entirely different from the law being true in the past. The latter is scientific. The former is not, as it is unsubstantiated by observations, and thus non-scientific, and neither can you deduced by logic that what holds today must necessarily hold tomorrow, but its basis is mere faith, namely that the laws will remain true to us in the future.
Having said all that, have you guys heard of the N-body problem? It is a mechanistic problem, where every interaction between the bodies are completely described by Newtonian laws. The problem is to predict exactly where each body will be for all times. It was found to be unsolvable, ie we cannot know or predict the position and velocity of each of the N bodies at any time, even when we have known everything about the laws governing their motions and positions.
Now this problem does not mean the world is not deterministic but only that it is humanly unknowable. The same applies to chaos. We just do not know the systemic impact of a perturbation in a system, but only the system “knows”.
Laws of nature may contain general concepts, such as “mass”, “color”, “aptitude”, “capital”, “diabetes”, “return on investments”, etc.; but may not contain such terms as “the Fraser River”, “the planet Earth”, “$59.22”, “June 18, 1935”, “IBM”, etc. That certain chicken or that farmer are not general concepts and this example is neither a universal nor a statistical claim.
chanbeng; physical laws (laws of science) and laws of nature are not the samething.
electrons bear the electrical charge -1.6 x 10-19, this is a law of nature. It is of the very ‘nature’ of an electron, by necessity, to have this particular electrical charge. in any time or place, this law will hold because it is universal.
Raistlin,
Once again you have given me no reason to believe that the electron will maintain the same charge tomorrow. I believe very strongly that it will do, but there is no certainty that it will. You are asserting very strongly that it will, but you still have not given any sense of proof for these so called universal laws which will hold for all time. In 500 years time the charge of an electron may change, how can you refute that?
- ben
How about: I predict that when I flip this coin, something or nothing will happen
Is that not 100% accurate?
I’d say about 99% of a chance that something will happen, but not 100%.
Yes it is, but you’ve just listed all possible outcomes. It is the equivalent in the current argument to saying “When I heat sulfur it will or will not boil at 444.6 degrees” There’s nothing fancy about that, it’s just an application of logic. A AND ¬A is always True. The first post was asking about predicting things based on past events.
I take your point, that there is something we can know deductively, but i’m not arguing that we can’t know anything for certain, i’m saying that inductive reasoning is not 100% certainty.
- ben
because having that certain charge is NECASSARY for the electron to be what it is, just like having 4 sides is necassary for a square for being a square. it is not a contingent kind of truth, it is necassary. if it had any other charge, it wouldn’t be an electron.
these analytic definitions are necessary:
“squares have for sides”
“electrons bear the electrical charge -1.6 x 10-19”
they define the meaning and are necessarily true.
these analytic definitions are contradictory:
“squares are round”
“electrons bear the electrical charge of 1”
Necessary truths cannot be otherwise.