04 Mar 15
Originally posted by bbarrI disagree. If we are talking about infallible knowledge, then the knowledge of an action does render the action necessary. If we are not talking about infallible knowledge then we might as well not call it knowledge. I realize it is reasonable to use the word knowledge when we are fairly sure of something, but in this case if Gods knowledge is not infallible, then he shouldn't even have a clue. I don't have libertarian free will if I have a 99.99999999999% chance of drinking coffee tomorrow. I can't honestly say 'well I could choose not to.'
I don't see how. From (5) it follows that S will, in fact, A. But it doesn't follow that it is necessary that S will A. God's knowledge (or my knowledge, for that matter) of the fact that S will A doesn't change the modal status of the fact that S will A. It doesn't render it necessary.
04 Mar 15
Originally posted by twhiteheadYou've missed the factive nature of knowledge. If I say I know something then it means that it is required to be true. It's part of the definition of knowledge. God's infallibility is a statement about God, not about his knowledge.
I disagree. If we are talking about infallible knowledge, then the knowledge of an action does render the action necessary. If we are not talking about infallible knowledge then we might as well not call it knowledge. I realize it is reasonable to use the word knowledge when we are fairly sure of something, but in this case if Gods knowledge is not infall ...[text shortened]... 99999999% chance of drinking coffee tomorrow. I can't honestly say 'well I could choose not to.'
When a scientist makes a claim such as "We know electrons exist." there are unstated caveats about what an electron is (an elementary excitation of an effective quantum field theory seen at energy scales below the Electro-weak scale) or with statements like "We know smoking causes cancer" is short for "We know that smokers are 20 times [1] more likely to develop cancer with a confidence of p < 0.01." the additional confidence criteria protect the truth value of the statement. Theories cannot be said to be true as contradictory future evidence cannot be ruled out so the truth value is uncertain.
[1] I made up these numbers for the sake of the post, it's something like that.
04 Mar 15
Originally posted by DeepThoughtWell if that is the definition then bbarr is wrong.
You've missed the factive nature of knowledge. If I say I know something then it means that it is required to be true.
He says:
I don't see how. From (5) it follows that S will, in fact, A. But it doesn't follow that it is necessary that S will A.
I say that if S will A then S necessarily will A.
04 Mar 15
Originally posted by twhiteheadDeep Thought was just speaking loosely. If I know P, then it follows that P is true. To say that P is "required" to be true means merely that the inference here from "I know P" to "P" is valid. Valid inferences are necessarily truth-preserving, so if it is true that "I know P", then it follows necessarily that "P". But it does not follow that P is a necessary truth rather than a contingent truth. Again, just because I know P it doesn't follow that P is true in every possible world.
Well if that is the definition then bbarr is wrong.
He says:I don't see how. From (5) it follows that S will, in fact, A. But it doesn't follow that it is necessary that S will A.
I say that if S will A then S necessarily will A.
04 Mar 15
Originally posted by twhiteheadMmm., sloppy phrasing now I look at it, there's an impicit clause at the end. The sentence should have read:
Well if that is the definition then bbarr is wrong.
He says:I don't see how. From (5) it follows that S will, in fact, A. But it doesn't follow that it is necessary that S will A.
I say that if S will A then S necessarily will A.
If I say I know something then it means that it is required to be true in order for the knowledge claim to be valid.
04 Mar 15
Originally posted by bbarrIt does follow, if we are talking about every possible world in which you know P. It seems to me to be irrelevant that there are possible worlds in which you do not know P and in which P is false.
Again, just because I know P it doesn't follow that P is true in every possible world.
More importantly, if there is only one world, the so called 'possible worlds' become irrelevant.
04 Mar 15
Originally posted by DeepThoughtSo are you saying that the knowledge claims in question may not be valid? When we say God knows P, then is it possible that the knowledge claim is not valid?
If I say I know something then it means that it is required to be true in order for the knowledge claim to be valid.
04 Mar 15
1 edit
Originally posted by DeepThoughtFor example, an infallibility condition on S's knowledge such as "Necessarily, if P then S knows P" , or some modified variant, seems to accomplish this globally.This implies omniscience rather than infallibility. Someone can be infallible, but not know everything.
I think we agree that, since knowledge is factive, to say that I know s ...[text shortened]... ly add necessarily if Alice is infallible because she is a goddess and not just a lucky guesser.
I think we agree that, since knowledge is factive, to say that I know something already implies the something is true. So the adjective infallible doesn't add anything in a sentence fragment like "God's infallible knowledge ...". So I feel that it must apply to an agent making assertions or as an adverb to the making of the assertions.
Yes, knowledge is factive. However, no, it does not follow that 'infallible' adds nothing when predicated unto knowledge. For example, infallibilism is a thesis regarding knowledge, and in a general form it requires for knowledge the satisfaction of some justificatory condition, such that it is not possible both that S satisfies this condition and that P is false. Please note how modality is built into the very fabric of this. Clearly, then, 'infallible' adds a lot here, since this is a strong condition on the circumstances under which the knowledge is held.
So it must simply be a consequence of always being right.
There can be different senses of the term 'infallibility'. What you are describing is consistent only with weaker forms of the term, in which it is sufficient for one's being infallible that it contingently be the case that one happens to always be right. What you describe here is not consistent, however, with the stronger sense of the term, since it makes no provision that there is immunity from the possibility of error.
I do not think that modal operators add much here.
I think they add a tremendous amount. They can get us from your weak form of infallibility to a very strong sense of the term. There's a big difference between saying that S happens to be right all the time; and saying that S is always right and furthermore is free from even the possibility of being mistaken. The latter is a much stronger condition, and will be the relevant one in many of these and related discussions. If you think this stronger sense of the term can be divorced from modality, then I would be interested in hearing your thoughts on that. If you probe the literature on, e.g., infallibilism as a thesis regarding knowledge, modality is built right in. Offhand, I do not see a good way of escaping this.
So to encode infallibility we need some predicates. Alice is a named object a. S means is a statement, B(x,y) x belongs to y, T(x) would be x is true. F(a) would be Alice is fallible, so ¬F(a) denotes Alice's infalliblity. Then Alice's infallibility would be encoded as:
∀x (S(x)&B(x,a) -> T(x)) <-> ¬F(a)
Again, this only works for a weak sense of the term that is often irrelevant or easily dismissed in these discussions. Your encoding is fine if by Alice's being infallible we just mean that all statements belonging to Alice happen to be true. Your encoding only ties infallibility to the fact that all of Alice's statements are true. But a stronger condition would provide that Alice cannot be wrong; that it is not possible that she is wrong. Such is not satisfied just in virtue of all of her statements being correct. And these extra constraints require modal interpretation, in light of terms like 'cannot' or 'not possible'.
When a theists states, say, that God is infallible, does he or she intend merely that God happens to always be correct? Or do they intend further constraints, such as that God could never be wrong? If such further constraints are intended, then modality is an integral part of this.
04 Mar 15
Suppose that whenever there is milk in the fridge, the following day, I will have coffee, and this is always the case. I look in the fridge and note that there is milk. I now know without a doubt that I will have coffee the following day. One could say that my knowledge did not cause me to have coffee (the milk did perhaps? ) Nevertheless, once I knew there was milk in the fridge, my having coffee the next day became a certainty and I lost any free will on the matter.
Which part of this is being disputed by those that say free will and fore-knowledge are compatible, or which part is an inaccurate representation of what is being discussed?
04 Mar 15
Originally posted by twhiteheadDo you think it is possible to know contingent truths?
It does follow, if we are talking about every possible world in which you know P. It seems to me to be irrelevant that there are possible worlds in which you do not know P and in which P is false.
More importantly, if there is only one world, the so called 'possible worlds' become irrelevant.
05 Mar 15
Originally posted by twhiteheadIt is stupid to think that free will is not being exercised if one knows in advance what one is going to choose. 😏
Suppose that whenever there is milk in the fridge, the following day, I will have coffee, and this is always the case. I look in the fridge and note that there is milk. I now know without a doubt that I will have coffee the following day. One could say that my knowledge did not cause me to have coffee (the milk did perhaps? ) Nevertheless, once I knew th ...[text shortened]... wledge are compatible, or which part is an inaccurate representation of what is being discussed?
05 Mar 15
1 edit
Originally posted by twhitehead
It does follow, if we are talking about every possible world in which you know P. It seems to me to be irrelevant that there are possible worlds in which you do not know P and in which P is false.
More importantly, if there is only one world, the so called 'possible worlds' become irrelevant.
More importantly, if there is only one world, the so called 'possible worlds' become irrelevant.Possible world semantics are a way of making sense of modal logic. Suppose we toss a coin and it comes up heads. What do we mean when we say something like: "The coin was not necessarily going to come up heads."? After all it did come up heads so we are discussing something counter-factual. The idea of possible world semantics is to give us a way of interpreting sentences like that. The possible worlds are not required to be real. So we toss the coin and in the actual world it comes up heads. But we can discuss a possible world where the coin came up tails, and since we can imagine it one where it balances on its edge. Then necessarily is interpreted to mean "in all possible worlds" and possibly to mean "in at least one possible world". Basically this is a way of making precise statements about counter-factual or future scenarios where there is more than one thing that could happen.
05 Mar 15
Originally posted by DeepThoughtWhich is why I earlier stated that the issue may not be one of logic at all.
Possible world semantics are a way of making sense of modal logic.
Suppose we toss a coin and it comes up heads. What do we mean when we say something like: "The coin was not necessarily going to come up heads."?
I don't know. In the case of a single universe with a single timeline, you are not making sense. The coin did come up heads and that's that.
After all it did come up heads so we are discussing something counter-factual. The idea of possible world semantics is to give us a way of interpreting sentences like that.
But what do you mean by it?
The possible worlds are not required to be real.
They are required to be possible. In other words, there cannot be a 'real' world either at the time you are considering them.
So we toss the coin and in the actual world it comes up heads. But we can discuss a possible world where the coin came up tails, and since we can imagine it one where it balances on its edge.
Can we? Why? What makes you think such worlds are 'possible'?
What if the coin simply disappeared? Is that also a 'possible world'? If not why not?
Basically this is a way of making precise statements about counter-factual or future scenarios where there is more than one thing that could happen.
But if there is only one timeline then there is no scenario in which more than one thing can happen. So making precise statements about them is a useless exercise (as well as being wrong).