The pragmatic approach is motivated by the view that the nature of an argument cannot be completely captured in terms of its structure. In contrast to structural definitions of arguments, pragmatic definitions appeal to the function of arguments. Different accounts of the purposes arguments serve generate different pragmatic definitions of arguments. The following pragmatic definition appeals to the use of arguments as tools of rational persuasion (for definitions of argument that make such an appeal, see Johnson 2000, p. 168; Walton 1996, p. 18ff; Hitchcock 2007, )
Logos (plural: logoi) is logical appeal or the simulation of it, and the term logic is derived from it. It is normally used to describe facts and figures that support the speaker's claims or thesis. Having a logos appeal also enhances ethos because information makes the speaker look knowledgeable and prepared to his or her audience. However, the data can be confusing and thus confuse the audience. Logos can also be misleading or inaccurate, however meaningful it may seem to the subject at hand. In some cases, inaccurate, falsified, or miscontextualized data can even be used to enact a pathos effect. Such is the case with casualty numbers, which, while not necessarily falsified, may include minor casualties (injuries) that are equated with deaths in the mind of an audience and therefore can evoke the same effect as a death toll.