The prime function of human communication is to enable people to survive their environment. The special function of an argument is to adjust the environment to satisfy felt needs. Whether argument takes the cognitive form of thought, the textual form of an essay, or the interpersonal form of a conversation, it serves this general function. Specific functions of an argument include claim, data, warrant, objection, support, and qualification. These functions assume identity in cognitive, textual, and interpersonal argumentation. For example, the primary function of claim assumes a belief in cognitive form, a proposition in textual form, and an utterance in interpersonal form. The target of an argument may be one's self, a nonpresent other, or a conversational partner. The functional theory of argument views the function to be the same in all three forms--to adjust the environment to satisfy felt needs. Therefore, the three forms of argument are not different things, rather they are different types of the same thing. (HOD)