Relationship between Necessary Assumption and Strengthen Questions

ahnendc-1

Hey everyone! Curious as to what your thoughts on the following question:

Do ALL necessary assumptions strengthen an argument? (NA -> Strengthen)

Obviously, necessary assumption prevent your argument from collapsing but does this strengthen an argument per se? To use J.Y.'s example - I play basketball, therefore, I am the best Basketball player in the world - for all intents and purposes there are an infinite amount of necessary assumptions (I am alive, I have two hands and two feet, I can dribble, I actually inhabit THIS world, etc.) does patching up one of those holes necessarily strengthen the argument?

I understand that to qualify as strengthening the additional support can be VERY subtle does precluding the death of the argument so to speak necessarily entail additional support?

Interesting to contemplate but if you believe that all necessary assumptions questions strengthen an argument then contra-positively you must accept that if something doesn't strengthen the argument then it cannot be a necessary assumption (/Strengthen -> /NA)

However, I feel as if there are plenty of statements that do not strengthen but are still necessary (/Strengthen <-S-> NA). To fall back on J.Y's example, I inhabit this world; I feel as if this does not strengthen the argument per se but obviously certainly necessary.

What prompted this post was [SPOILER ALERT FOR PT75] question number fifteen on the first logical reasoning section; the answer choice is practically a necessary assumption.

What are your thoughts?

Logician

Hey there
I do believe all necessary assumptions strengthen the argument, if ever so slightly. like you mentioned above, if you strengthen an argument in even the most subtle and, for lack of a better term "weak" way, you're still strengthening the argument, which is precisely the manner in which NA's strengthen arguments. If you had a scale exhibiting the level at which an argument is strengthened, NA would be on the extreme left of the scale, strengthen Q's would be somewhere in the middle, PSA's closer to the right and SA at the extreme right (validity). In the example you gave above "I inhabit this world" it does add some support to the argument, as it makes it more believable that you are the best basketball player in the world, how? by stating that you meet one of x number of requirements, without which you could not be the best basketball player in the world.

ahnendc-1

@Logician thanks for your input; I think your reasoning makes sense here..

Also, I probably should have asked in the original post but do we have a sense as to what LSAC's viewpoint on this is? Based on PT75-1-15 (also potentially, 75-1-9), I think they might concur with you.

NerfThis

I suppose you could see NA being used to strengthen the argument however personally I see it as essential rather than mere stregthen. In otherwords, the lack of the NA will make the argument useless. Strengthening inplies theres a range on the amount of strengthening added, a non dichotomy. On the other hand, I see NA as a dichotomy. Its either or, as in the assumption allows the argument to stand, without it there is no argument.

With that said,
Should introducing NA be seen as strengthening? Perhaps.

Should the lack or taking away of an NA be seen as weakening? Absolutely. I'd say its probably the most weakening you can do to an argument.

Markmark

@Logician said:
Hey there
I do believe all necessary assumptions strengthen the argument, if ever so slightly.

Ditto - the fact that a NA is currently present in a situation does strengthen the argument but almost not at all