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A premise or premiss [a] is a proposition—a true or false declarative statement—used in an argument to prove the truth of another proposition called the conclusion. [1] Arguments consist of a set of premises and a conclusion. An argument is meaningful for its conclusion only when all of its premises are true. If one or more premises are ...
From the example above, humans, mortal, and Greeks: mortal is the major term, and Greeks the minor term. The premises also have one term in common with each other, which is known as the middle term; in this example, humans. Both of the premises are universal, as is the conclusion. Major premise: All mortals die. Minor premise: All men are mortals.
A proposition that asserts the truth of a statement, as opposed to negating it. [7] [8] [9] affirming the consequent A logical fallacy in which a conditional statement is incorrectly used to infer its converse. For example, from "If P then Q" and "Q", concluding "P". alethic modal logic
Consider the modal account in terms of the argument given as an example above: All frogs are green. Kermit is a frog. Therefore, Kermit is green. The conclusion is a logical consequence of the premises because we can not imagine a possible world where (a) all frogs are green; (b) Kermit is a frog; and (c) Kermit is not green.
For example, the rule of inference called modus ponens takes two premises, one in the form "If p then q" and another in the form "p", and returns the conclusion "q". The rule is valid with respect to the semantics of classical logic (as well as the semantics of many other non-classical logics ), in the sense that if the premises are true (under ...
The first type of enthymeme is a truncated syllogism, or a syllogism with an unstated premise. [6] Here is an example of an enthymeme derived from a syllogism through truncation (shortening) of the syllogism: "Socrates is mortal because he's human." The complete formal syllogism would be the classic: All humans are mortal. (major premise ...
To show that this form is invalid, we demonstrate how it can lead from true premises to a false conclusion. All apples are fruit. (True) All bananas are fruit. (True) Therefore, all bananas are apples. (False) A valid argument with a false premise may lead to a false conclusion, (this and the following examples do not follow the Greek syllogism):
For example, "Snow is white" (in English) and "Schnee ist weiß" (in German) are different sentences, but they say the same thing, so they express the same proposition. Another definition of proposition is: Two meaningful declarative sentence-tokens express the same proposition, if and only if they mean the same thing. [citation needed]