I am studying Logic now and I have some terminology I want to ask about:

  1. Proposition

  2. Compound proposition

  3. Statement

  4. Assertion

  5. Argument

I know that a proposition is a simple declarative sentence that could be said to be true or false. I know also that a compound proposition is a proposition formed from the negation, conjunction or disjunction or other compound propositions.

My question what is the relationship between a statement and compound proposition?

The book I am reading from uses the word statement with the conditional statement, but the conditional statement could be reduced to a compound proposition but it never uses compound proposition with the conditional statement.

Also I am confused between assertion and proposition and I want to know the relationship of the word argument to all that.

  • I'd suggest you research your question on the web a bit.
    – Hot Licks
    Dec 2 '16 at 20:46
  • 1
    try Philosophy SE.
    – user175542
    Dec 2 '16 at 20:59

These words are all used in logics of various kinds, but they aren't all logical terms.

The first three are all about the same kind of idea, but expressed semantically, syntactically, and pragmatically. Only the semantics is truly logical.

  • Proposition is basic logic, as you say; Compound Proposition is an unimportant variant; it means it's a more complex proposition than usual, the same way f(g(x)) is a compound function of x. This is the semantic expression.

  • Statement is the linguistic equivalent of a proposition; it's one type of linguistic utterance, like Question or Order. It's not a logical term, because logic assumes that any declarative sentence can be either true or false, and that there are no other kinds of sentences. This isn't the case, but it's a useful fantasy in certain situations. This is the syntactic expression (in that it picks out one type of English syntax, and leaves out most of the rest).

  • Assertion is the speech act of uttering a statement with evidence of intent to convince the addressee that the speaker believes the statement to be true. It's a metalogical symbol, in that it can appear in syllogisms and pragmatic rules, but isn't part of propositional or predicate calculus. This is the pragmatic expression.

Argument, by contrast, is a term of logic (and mathematics), and doesn't refer to arguing. Rather, an argument is part of a proposition in Predicate Calculus. Almost all predicates have arguments.

If the statement is
  All men are mortal
then the complex proposition in logic is
  (∀x : Man(x)) Mortal(x)
(this would be read as "For every x such that Man of x, Mortal of x")
where x is the argument of the predicates Man and Mortal.
The proposition "Man of x" means "x is a man", and the other means "x is mortal".
Predicate adjectives and nouns are predicates and take arguments, just like verbs take subjects.
In fact, it makes sense to think of Subject and Object as arguments of the verb phrase.

  • Thanks for your answer ... but can I conclude that from a logic point of view : proposition/compound proposition/statement semantically are the same .. but assertion is proposition + claiming it's true ... also i'd like to mention denial is proposition + claiming it's false ....argument is a conditional statement that has All the premises and conclusion claimed to be true to make the argument true ? i was just trying to summerize and make sure of my interpretation. thanks
    – Eng_Boody
    Dec 2 '16 at 22:40
  • I have done some search again and I found that statement is a sentence through which some one is declaring something , proposition is a statement that could be judged to be true or false ... but pls give me the branches(types) of statements in English language ... proposition and conditional are two of them but what are the others ? thanks
    – Eng_Boody
    Dec 2 '16 at 23:06

Not the answer you're looking for? Browse other questions tagged or ask your own question.