The Definition Argument answers the questions "What is it?" "What category does it belong to?" In other words, the Definition Argument attempts to assign a specific case to a larger category because it shares the essential characteristics of that category. Examine the following definition claim:
The definition argument requires that we generate a list of essential criteria of the y term (category). Thus, the essential criteria of an environmentally-unsound farming practice might look like the following:
The underlying structure of the definition argument's enthymeme can be expressed as x is y because it possesses the characteristics A, B, C, D, . . .
The definition argument has two areas of major concern: 1) the criteria and whether they sufficiently characterize the y term (category), and 2) the match, or whether the x term (specific case) actually possess the criteria.
In the above example, our concern about the criteria might lead us to question whether the category of environmentally-unsound farming practices need be characterized by "significant or irreparable" damage. Perhaps, we could argue, any damage at all constitutes an environmentally-unsound farming practice. Notice that, at this point, the discussion of the criteria isn't concerned at all with the x term (hog factory) at all. Rather, the criteria discussion focusses on accurately characterizing the y term (category).
During the match
portion of the definition argument, on the
other hand, our concern is to demonstrate that the criteria apply to the
x term (hog factory). We are obligated to prove that a hog farm does indeed
damage the environment, that such damage is significant, that it threatens
area wildlife, and that it poses health risks to nearby human populations.