Mill’s Maxim on Philosophy15

Talisse and I have been thinking about the famous maxim from John Stewart Mill’s On Liberty that

He who knows only his own side of the case, knows little of that. His reasons may be good, and no one may have been able to refute them. But if he is equally unable to refute the reasons on the opposite side; if he does not so much as know what they are, he has no ground for preferring either opinion.

We call it Mill’s Maxim.  It’s a central feature of our Why We Argue book, and we have a short popular essay on it published in Think a few years back.  Over at Philosophy 15, we have a 3-part discussion of the maxim, where Talisse argues that the maxim has two components.  First, it’s an epistemic thesis – that evidential assessment is comparative, and so to know the case for one’s view, it’s always how one view handles the relevant evidence compared to the competitors.  Second, it’s a semantic thesisthat understanding a view is to understand it contrastively, in terms of the views it must exclude.

In the spirit of the maxim, in the subsequent videos I then subject the view to a series of objections and contrasts in terms of how the view may be supererogatory instead of obligatory, how it may overplay the necessity of contrasts for comprehension, and whether the maxim puts us in danger of falling for really bad views.

Finally, there’s a question of whether the demands of following Mill’s Maxim places unnecessary or undue burdens on members of vulnerable groups.

3 thoughts on “Mill’s Maxim on Philosophy15”

  1. Great stuff.

    Just a thought, my guess is that the maxim is to be read normatively–you should know the other case *well* (when relevant). Descriptively, I think everyone has got a ready-made hollow man on the alternatives. And, not to plug this more than I should, everyone begins by thinking they’ve got a good grasp on the other case (and everyone thinks everyone else is a relativist, etc.).

    *edit: “I should”

  2. Hey John,

    This is a good observation — that the Mill line is more about a requirement of cognitive command, rather than knowledge.

    Here’s how I’d want to make the case that it’s a requirement for knowledge. Think of the Maxim as a dialectical version of the requirement of reasons distinguishing between relevant alternatives. So if your evidence about what I had to drink for lunch was that it was brown and fizzy, you would know that I had a cola, and not water or tea. You may not know which brand of cola, but you do know at least what it wasn’t.

    The same, presumably, would go for dialectical conditions, in that if you don’t know what the dialectically relevant alternatives there are, you don’t know what the evidence supports or not. And perhaps stronger: if there are others out there with reasons that defeat your reasons (or to which you don’t have answers), you don’t know. So consider those old Gettier cases where your friends have some misleading evidence, but you’re not aware of their having the evidence…

  3. The trick, of course, is that (to modify Peirce somewhat), people think themselves sufficiently apprised of the alternatives (until they’re not).

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