Identify the Flaw - Can there be more than one correct

[brian.atchley]

assumption or gap? Or is there only one absolute, specific assumption that is made that links the premise to the conclusion?

For example:

Marbles were extremely rare in Mesopotamia,
therefore
those who possessed them were wealthy.

The answer given in interact is: The argument assumes that only wealthy people possessed rare items.

Is that the only correct and precise assumption made? Can't there be other assumptions as well? Such as:

Assumes rare = valuable


Another example:

Cats are friendlier than dogs, therefore cats are the best pets.

Is only one correct gap or assumption made here, or are there several such as:

Assumes friendliness is valued most of all attributes
Assumes only two types of pets exist, cats and dogs
Assumes friendliness is all that matters to humans
Assumes friendliness is a good attribute to have for a pet

(or maybe some of the assumptions listed above are not quite/exactly an assumption made by the argument)


Also, I am trying to wrap my head around how necessary assumptions and sufficient assumptions relate to my question here.

[ManhattanPrepLSAT1]

Hey Brian, good questions. First, there is not one and only assumption in any given argument. In fact, there are typically quite a few assumptions made within each argument.

Second, Necessary Assumptions will express an idea the argument's reasoning cannot live without. There are often many ideas that the argument needs to assume are true, in order for the reasoning to stand--so be flexible and don't get bogged down if the one assumption you identified while you evaluated the argument's reasoning is not there.

Sufficient Assumptions will express an idea that if you add it to the argument, the conclusion will be proven 100%. The argument may not need the assumption as it may represent an idea that is stronger than what the argument needs, but nonetheless will do the trick.

Hope that helps!