Monday, January 27, 2014

Knowledge last: An argument

  1. If p partly grounds q and p is explanatorily irrelevant to r, then q does not strictly explain r.
  2. Something's being ungettiered is explanatorily irrelevant to all philosophically important facts, except for knowledge facts.
  3. That one's belief that p is ungettiered partly grounds that one knows p.
  4. So facts about what one knows do not strictly explain anything philosophically important.
The concept of strict explanation here is a kind of purification of explanation where irrelevant elements are removed. For instance, that George was late for work because George was mugged by a Polish-Canadian is not a case of strict explanation, because that the mugger was Polish-Canadian is irrelevant to explaining George's lateness.[note 1] But maybe it is a case of explanation. (Wes Salmon says that irrelevancy destroys explanation, but maybe sometimes it just renders it unstrict.)

So, in the order of explanation among philosophically important facts, knowledge facts come last, if at all.


Anonymous said...

I might be wrong, but I think there's a typo in (1). I think it should read "then q does not strictly explain r"

Alexander R Pruss said...

Hey, the premise this way was uncontroversial. Alas, the argument was invalid then.

Thanks for catching that. Fixed.

Brian Cutter said...

It seems plausible that various faculties of ours, e.g. our perceptual faculties, our faculties of rational intuition, our faculty of memory, etc., have the function of producing *knowledge* (about our environment, about moral and abstract truths, about the past), rather than merely true belief or anything else short of knowledge. One reason to think this is that there seems to be something defective about a perceptual (intuitive, mnemonic..) belief if it falls short of knowledge, even if it is true and justified. But if these faculties have the function of producing knowledge, that suggests that the notion of knowledge is philosophically important. Actually, we can make a stronger claim: this conclusion entails that knowledge *explains* things of philosophical interest, though the explanations in question are final-causal explanations. And I *think* if we take "strict explanations" to include final causal explanations, then premise (1) looks less plausible, but there are a lot of tricky issues here.

Even setting aside questions about the functions of various faculties, the mere fact that there is value to having knowledge over and above the value of having true beliefs, justified beliefs, etc., suggests that knowledge is philosophically important-- at least in the theory of value.

(One argument for the claim that the "mere fact" mentioned above is correctly so called: we take it to be among God's perfections that he is omniscient-- that he *knows* everything. And it seems that we can't fully capture what's great-making about omniscience by merely pointing out that it entails omni-correctness-- having a true belief with regard to every question-- or related properties which fall short of omniscience.

Alexander R Pruss said...


These are great comments.

I am inclined to deny that the faculties have the function of producing knowledge. Rather, they aim at truth, or justified truth.

I do not think there is anything defective with vision when it produces a credence 0.7 doxastic state that there is a tiger a mile away, even though that degree of credence appropriately falls short of knowledge. So not every falling short of knowledge is a defectiveness in a doxastic state. You might think that that's just because the credence 0.7 isn't a belief yet. Maybe. But here's presumably what happens when you approach the tiger, supposing it really is a tiger. The credence grows. It hits the threshold for belief. And then it hits the threshold for knowledge. The threshold for belief is lower than that for knowledge. (Quick argument: The threshold for belief is at least as low as the threshold for assertion. The threshold for assertion is slight lower than the default credence we should accord testimony. (Trent Dougherty and I have an argument for this.) But the default credence for testimony--with no track record data, etc.--seems lower than the threshold for knowledge. So, the threshold for belief is lower than that for knowledge.) And there was nothing defective when it was above the threshold for belief but not for knowledge.

I don't think that knowledge has a value over and beyond justified true belief.

Brian Cutter said...

Good points. Allow me to take another stab at these issues. I think the main intuition driving my original dissent was this:

(K) Necessarily, if one does not know a given truth p, then there is something imperfect about one's epistemic relation to p. ("Imperfect" is a more apt word than "defective." My ignorance about the exact number of particles in the universe renders me less than perfect, but it is not a defect in me.)

But on reflection I think we can accommodate this intuition while allowing that there is no value to knowledge beyond the value associated with justification and truth. For the following two claims seem plausible. (i) Necessarily, for any truth p, if one is not justifiably certain that p, then one's epistemic relation to p is less than perfect. (More generally, the greater the degree of justified certainty one has in a truth p, the more valuable/perfect is one's epistemic relation to p.) (ii) Necessarily, if one is justifiably absolutely certain about some truth p, then one knows p. (Justified certainty seems to be inconsistent with Gettierization.) From (i) and (ii), we can recover (K) without supposing that the aspects of knowledge which go beyond justification and truth contribute to its value.

The cases I had in mind when I claimed that there is something defective about a perceptual belief that falls short of knowledge were Gettier-ish cases of "veridical hallucination," e.g. a case in which I hallucinate a dog, justifiably believe on the basis of my experience that there's a dog before me, and coincidentally there really is a dog before me. Your points have convinced me that I didn't quite draw the right lesson from these cases. But I still think there is something imperfect about the resulting doxastic state in these cases of veridical hallucination (beyond the obvious defectiveness in the *visual system*). In particular, the doxastic state does not involve *acquaintance* with the state of affairs they are about. (I might further suggest that it is the function of perception to acquaint us with the states of affairs that obtain in our environment. If so, then it may follow that the resulting state is not just imperfect, but defective.) And it seems plausible that one (more) necessary condition on having a perfect epistemic relation with a truth p is that one is acquainted with the state of affairs that p. (By "acquaintance" I don't mean here exactly what Russell means; Russellian acquaintance is a person-object relation and mine is a person-state-of-affairs relation. In my sense, to know p by acquaintance is to know it "by sight" [perhaps metaphorically] as opposed to by any indirect means, e.g. "by faith" (in another's testimony) or by inference of any kind.)

Putting all this together, I would tentatively want to say that a necessary *and sufficient* condition for being perfectly epistemically related to a truth p is that one is acquainted with the state of affairs that p (fully, if acquaintance comes in degrees) and one is justifiably certain that p. Probably each of these individually entail knowledge in p.

Heath White said...

I would think being gettiered would undercut both understanding and whatever it is we want to call the end of our cognitive faculties. And I would think something in this neighborhood would be philosophically interesting.

(I have no great brief for the importance of *knowledge* -- I tend to think it's most interesting to consider the function of "knowledge"--but I don't like this argument for the deflationary conclusion.)

Alexander R Pruss said...


Suppose unbeknownst to you you learn all your quantum mechanics from a book typed by monkeys that happens to be word for word exactly like an excellent quantum mechanics textbook. If you understand that book, you understand quantum mechanics. But you don't know any quantum mechanics. Gettier cases do not seem to undercut understanding (much as they don't undercut know-how).

Alexander R Pruss said...


One can have cases of Gettiered perceptual belief where there is still acquaintance. For instance, when you're looking at the only barn in barn facade county.

Or (more generally?) consider cases where you're acquainted with a state of affairs, but there is a defeater which doesn't take away acquaintance, only knowledge, and you have a justified Gettiered true belief that you have a defeater for the defeater.

I think (K) is compatible with what I was claiming. To challenge my claim, you would need something stronger like:

(K*) Necessarily, if one does not know a given truth p, then *because of this* there is something imperfect about one's epistemic relation to p.

But your argument doesn't establish (K*), but only (K).