Argument   

What is an argument? Let us begin with an example of an argument on the issue of nature vs. environment  (examples taken from Kahane and Cavender’s Logic and Contemporary Rhetoric):
    1.) There is a set of identical twins that have different IQ test scores.
    2.) Identical twins have the same genes.
    3.) Therefore, the environment must have some influence in determining IQ.
Statements 1 and 2 are called premises and statement three is the conclusion. The conclusion asserts the claim that is supported by the premises. Sometimes arguments have an implied premise(s). For example, consider the argument:  The barometer is falling sharply, so the weather is going to change:
    1.) The barometer is falling sharply.
    2.) Therefore the weather is going to change.
The implied premise of course is: Whenever the barometer falls sharply, the weather changes.

Logic link:
Critical Thinking Core Concepts