Can a necessary assumption also be a sufficient assumption?

abdehi0718

And vice versa?

Louislepauvre

Necessary can be sufficient, but I don’t think a sufficient can be necessary. I’d love to hear others thoughts on this though.

Maitotoxin

I suppose a sufficient assumption can be a necessary assumption if that sufficiency is singular (no other sufficiency exists).

MissChanandler

Yes- and saying that something is "necessary and sufficient" is exactly the same as saying something is "sufficient and necessary"

LSATcantwin

@MissChanandler said:
Yes- and saying that something is "necessary and sufficient" is exactly the same as saying something is "sufficient and necessary"

I think this sufficiently answers the question but it might not necessarily go into enough detail

(Honestly just wanted to play with the words - I think it's a great answer)

studyingandrestudying

Short answer, yes--sometimes.

J_Clarkson

@MissChanandler said:
Yes- and saying that something is "necessary and sufficient" is exactly the same as saying something is "sufficient and necessary"

A certain philosopher on PT 69 would like to have a word about this!

ALEXAN.S

Yes, its called a bi-conditional. They are covered in the "advanced logic" portion of the syllabus. An example would be "A if and only if B," or A<--->B.

Peaceofmind

Yes. Sometimes the two overlap. You can think about it this way: if you want to buy a lollipop that costs $50, having $49 in your wallet is necessary, but not sufficient. Having $50 will be necessary AND sufficient. Having $51 will be sufficient, but no longer necessary. Something like that.