Comments on the Maverick
The 'is' in 3. is tense-less, which could be seen as a grammatical error. Replace with 'was.' 4. then fails to follow.
Wow! A comment! Thanks, William. I agree that the inference from (2) to (4) is fallacious. But what do you mean by 'tenseless'? Bill V. uses this term a lot but I have never quite grasped how he intends it. Surely all verbs are tensed? You suggest replacing the 'is' in (3) with 'was'. Can this be a general rule? Suppose the argument started with 'James Dean is an actor'. Can we then infer 'There was somebody who is an actor'
Just saw this post."Is" is used equivocally. In statement 3, it does not mean "exists in the present time". But in statement 4 it is taken to mean that. That's equivocation.
Hello Im. Not sure I understand your suggestion. The word 'is' doesn't appear in (4), so how can there be an equivocation on 'is' between (3) and (4)?
In statement 4, the word 'exists' is a direct substitution for 'is'. And this is precisely where the transformation in meaning takes place. So, it is clear that the word 'is' has been used in two different senses. That's equivocation.
So your view is that (3) is true but (4) is false and hence the inference from (3) to (4) must be invalid?
It all depends on what the definition of the word "is" is. As used in statement 3, it clearly refers to something that does not exist in the present time. So to make a word substitution valid, you need to preserve that meaning. But statement 4 does not preserve that meaning. It only seems to be valid because you can usually substitute 'exists' for 'is', assuming that 'is' is defined as existing in the present time, which we typically do. Does that make sense?
Couple of points: first, what we are hoping to preserve in inference is truth rather than meaning. The move from 'James Dean is an actor' to 'Somebody is an actor' is truth-preserving but not meaning-preserving. Second, you say '...it [ie, the word 'is'] clearly refers to something that...' and I wouldn't want to say that 'is' refers to anything. But I think I get your drift. Can we agree that (a) sentence (4) is definitely false, and (b), there is something a bit woolly about the meaning of 'is' in (3) such that we can find some interpretation that makes (3) true and indeed a valid inference from (2)?
I agree that an inference need not preserve meaning, but statement 4 is not an inference - it is a restatement with a word substitution, and as such, it should preserve meaning.Nevertheless, I agree that we are dealing with imprecise language, and leads to the problem. So it would be better to use terms like the ones I used (like "exists in the present time"). In particular, statement 3 might be stated as "There was somebody who existed in the past, but no longer exists". Then, it would be impossible to make the next step to statement 4, because the more precise wording precludes it. But that's a good thing. One less example of faulty logic in the world.
Sorry to be so late replying. You asked what is meant when 'is' is tense-less. The English language uses the verb to be to apply to tense-less facts, like 2+2 is 4 or roses are red, and to things that have a being in our univere's spacetime, like "Obama is (as of this posting in 2016) the US President." Consider:Margaret Thatcher is the UK Prime Minister (currently false)Margaret Thatcher is a Prime Minister of the UK (a true historical fact, tense-less).Same word 'is', but the 'is' in the fact is tense-less, as in 5 + 5 is 10 or water is H2O.Your posting mixes the fact (synthetic a priori etc) 'is' with the tensed 'is', so it equivocates.