LOGIC COUNTERFACTUALS+INDICATIVE CONDITIONALS-PROBLEM

[LIND]

logic-COUNTERFACTUALS/indicatives -by Marius Manci

Indicative conditional= indicates what is (in fact) the case if its antecedent is (in fact) true

Counterfactual Conditional (or "if-then") statement= indicating what would be the case if its antecedent were true.

Here's a problem I sense with counterfactuals/indicatives in Logic.
2 Examples Conditionals/indicative+Counterfactual

#1.If I had not proposed to Lavi, then someone else would have.

#2.If Marius did not propose to Lavi, then someone else did.



The first example assumes that had the proposal not be done by me someone else would have. However this is clearly not necessarily true; perhaps no one else would have proposed to Lavi(exageration.

Yet despite the indicative in the second example (Marius did not propose) we don't have a clear evidence that Lavi has been proposed to. A ring is not a sufficient evidence that someone has been proposed to. If this is so, it follows that it is not necessarily true that when it comes to an *indicative counterfactual* we can confidently say that it is intuitively true that this is the case. Thus the antecedent is true (Marius did propose to Lavi) but it does not entail that this is in fact the case-namely that if I didn't propose then someone else certainly did.

 

[Ginkgo]

Are counterfactual/indicatives exclusive to cause-effect relationships? No cause-effect relationship can be known. However, this does not mean that cause-effect relationships do not exist. If we were to attempt an if-then statement about a cause and effect relationship, we would take a "leap of faith", assuming that the cause dictates the effect in any case.

Your first example assumes cause and effect. Both examples assume that Lavi was proposed to at all. There's no problem with your second statement as long as Lavi is essentially proposed to.

 

[Ginkgo]

.

 

[animenagai]

I don't really understand the objection, no one claims that counterfactuals are necessarily true. Like all propositions, they can be false. Look at these examples:

1. If Bob drew a closed 3 sided figure with straight lines it would have been a triangle.

2. If the duck was ate the bread, aliens would come and destroy the earth.

These are both counterfactuals, but one of them is clearly true, whereas the other is not. There is hence no automatic truth maker that comes with counterfactuals, like any sort of proposition. So when we look at your example,

#1.If I had not proposed to Lavi, then someone else would have.

Then you're right, there's no guarantee that this proposition is true. But we would we say that something's wrong with counterfactuals just because this proposition is false? Maybe I'm misreading your point and that we should just be more careful with counterfactuals, being more meticulous in examining their truth, in which case, I do wonder how liberal we are with counterfactuals to start off with. You got to remember that people say things they aren't fully committed to, we can't convert put any conversation into logical form. I could state sentence #1 for example just as a way of saying "Lavi's pretty hot so she has a damn good chance of being proposed to", which of course isn't as strong as the sentence may imply. To criticise one for making a counterfactual claim here would hence just be acting like a semantic nazi.

 

[BlueScreen]

#1.If I had not proposed to Lavi, then someone else would have.

#2.If Marius did not propose to Lavi, then someone else did.

They are obviously incomplete in terms of logic because they assume information not defined in the sentence.

- Assume groups A and B, (I or Marius) and (someone else) respectively. If not A, then B. If not B, then A.
- C represents Lavi.
- Action of A or B taken on C is proposed
- Someone is a set containing A and B.

A (not proposed) C is not necessarily equivalent to (not A) proposed C.

With a supporting sentence showing (A or B) proposed, ie. someone proposed, the statement can become complete. As shown below this is grouping the statement necessary to make the above statements equivalent with another "don't care" statement to simplify it.

(A or B) proposed C is equivalent to (A proposed C and B (not proposed) C) or (B proposed C and A (not proposed) C)

The only difference between the sentences is the subject and tense. In the future tense verification of the statement is impossible, though "Someone will propose to Lavi." as a supporting sentence will still complete the statement logically.

I admit a supporting sentence can look out of place and contains redundant information. So I agree, this form of statement is probably not the best choice if you want hard logic, but can be fun for writing, dreaming, guessing, wondering, chit-chat and most other things.