In argument, while motive and disposition might be interesting to study, they are of less interest than the stated positions.
Of course, a person may have all kinds of motives for adopting, questioning, rejecting, defending, or attacking a particular standpoint in a particular manner, but the only thing that person can really be held to is what he or she has, whether directly or indirectly, said or written. That is why it is not the internal reasoning processes and inner convictions of those involved in resolving a difference of opinion that are of primary importance to argumentation theory, but the positions these people express or project in their speech acts. Instead of concentrating on the psychological dispositions of the language users involved in the resolution process, we concentrate primarily on their commitments, as they are externalized in, or can be externalized from, the discourse or text. 54
from Eemeren and Grootendorst, Systematic Theory of Argumentation.