Assumption, presumption, premise, supposition... what is the difference?

[zebraZ]

Dictionary.com didn't help.

"I assume you are coming to my party."
"My supposition is that you are coming."
"I presume you are coming."
"My premise is that you are coming."

What's the difference?

Assume - take to be the case or to be true; accept without verification or proof; CAN ALSO MEAN; take on titles, offices, duties, responsibilities;

Supposition -a message expressing an opinion based on incomplete evidence; a hypothesis that is taken for granted; the cognitive process of supposing

Presume - To take for granted as being true in the absence of proof to the contrary:To constitute reasonable evidence for assuming; appear to prove: To venture without authority or permission; dare:

Premise - A proposition upon which an argument is based or from which a conclusion is drawn.
Logic.

Is this any good?

sorry - got that from DIctionary.com, which you said didn't help (oops)

Zebra, why?
I'd say assume is informal mainly and presume is more concrete than assume. If you assume someone's coming it's because you guess that they probably will. If you presumed you'd think it highly likely they would. Presume is more definite imo. Premise and supposition aren't the same at all, they're more formal and businesslike. What's wrong with those definitions?

isn't English a great language - so many ways to say the same thing, albeit with subtle differences that most of us miss completely .

Sorry zeb - no help at all !

OK

Premise is very formal and only really used in scientific terms, or when the sentence is clumsy if you use one of the others.

Supposition likewise is rather formal and general used in specific scientific situations. It is not quite the same as a premise - a premise is the starting point for an experiment, a supposition is something the experiment takes for granted

Finally the differnece between assume and presume is slight, and is mostly one of register (I think). Posh people say "presume", normal people say "assume".

how about that?

actually, no, as www says, presume is more definite.

But there is a register difference in there somwhere too.

I would use assume if I am telling someone I don't know all the exact details but am working on x being the case.

I would use presume if I was saying much the same thing, but telling them I know it might not be right and would expect them to correct me if they know otherwise.

Supposition and premise are nouns, the others are verbs, and give a slightly different way of stucturing the sentence. Supposition - equivalent to assume, premise more like presume.

But I have no idea what I am talking about

OK, I'm not 100% sure of this, but this is how I understand the difference.

An assumption refers to a belief that something will happen (I assume you are coming to my party = I believe you will come)

A presumption refers to a belief which is based on some prior knowledge ('I presume that you are coming to my party = I have reason to believe that you will come). So, yes, I agree that 'presume' is stronger than 'assume', because it suggests some foundation for the belief.

A supposition is something which you 'suppose'. So in this case the belief would be less strong again (more like 'I think you might come').

A premise is something which you are setting out to prove (in philosophical or scientific discourse). So if you say that your premise is that someone is coming to your party, I'd expect you to follow that up with the proof that that is indeed the case.

Does this help at all?

are you assuming that my presumption of the premise that a mumsnetter will know the answer to this quetion is all suppostion?

very clever, custy.
I write scientific papers and I get sick of saying "we assumed" all the time, so want to use alternatives, but wasn't sure of the meaning!!

I will come back and read this thread again when I'm not knackered.
Cheers.

ZebraZ

In that sort of context, I think you could use assume/presume interchangeably and suppose to suggest some doubt as to an outcome (e.g. 'supposing that the two chemicals were mixed at a high heat, an explosion might ensue' ... errrr... I'm not a scientist... can you tell? ).

I'd use 'premise' at the beginning of an article/paper etc. where you say what your aims/objectives are, e.g. 'my premise in this article is that Ellbell is definitely not a scientist, and I shall set out to prove this in the following way...'.

Another good word for that (well, one I use quite a lot) is 'contention' ('it is my contention that Ellbell is no scientist...' or 'in this article, I shall contend that Ellbell should really stop giving these stupid examples and go to bed').

Night night!