Fumerton’s “What the Internalist Should Say to the Tortoise.”

2024-1 Seminar Epistemology

 

1. Fumerton’s Inferential Internalism

① The distinction between inferential/non-inferential justification: in general, deduction, induction, and abduction (also known as “inference to the best explanation”) are enumerated as instances of inferential justification. Non-inferential justification, on the other hand, include a justification through sense perceptions, memory, introspection, etc. It is often said that the crucial difference between them is whether proposition serves as a medium in the process of justification. Fumerton, for instance, formulates inferential and non-inferential justification as follows: “A belief that P is inferentially justified if its justification is constituted by the having of at least one belief other than P. A belief is noninferentially justified if its justification does not consist in the having of any other beliefs” (Fumerton 1995: 56).

② The principle of inferential justification and its implication: “To be justified in believing one proposition P on the basis of another proposition E, one must be (1) justified in believing E and (2) justified in believing that E makes probable P” (note that entailment is the upper limit of making probable). (Fumerton 1995: 36; see also Fumerton 2015: 209).

Fumerton takes this principle as “a very general proposition of normative epistemology” and claims that it “plays an integral role in the famous regress argument for foundationalism” (Fumerton 1995: 56, 85). To be justified in believing P on the basis of E1, one also needs to be justified in believing E1. But the belief in E1 should be justified based on another piece of evidence, say, E2, and so on. Thus, we now encounter the problem of infinite regression. There are four possible responses to this problem:

(1) The process of justification indeed goes on infinitely: “Finite minds cannot complete an infinitely long chain of reasoning, […] we would have no justification for believing anything” (Fumerton 1995: 57).
(2) Our beliefs are ultimately based on some piece of unjustified evidence: again, it amounts to nothing but saying we would have no justification for believing anything.
(3) Such regression is circular, i.e., A is justified owing to B, B is justified owing to C, and C is again justified owing to A: then A is eventually justified by itself. In other words, A cannot be justified by any piece of evidence other than A.
(4) “There is a kind of justification for believing a proposition that does not consist, even in part, in the having of another different justified belief” (Fumerton 2015: 215). This doctrine is the heart of foundationalism.

It is also worth noting that Fumerton’s principle is twofold, i.e., “one needs to be not only justified in believing E, but justified in believing that E makes probable P” (Fumerton 2015: 209). The second clause of the principle of inferential justification is required to block illegitimate inference. Consider, for example, astrologers make a prediction p on the basis of information about people’s date of birth E and believe that p is true. Then “we will reject our astrologer’s beliefs as unjustified for the reason that the astrologer has no reason to believe that there is a probabilistic connection between astrological evidence and astrological predictions” (Fumerton 1995: 87; see also Fumerton 2015: 212).

 

2. The Tortoise’s Challenge to Inferential Justification

③ Carroll’s Tortoise and attempts to solve this Puzzle: in his article “What the Tortoise said to Achilles,” Carroll presents a skeptical argument that undermines any type of inferential justification. The basic form of this challenge is as follows: suppose we use Modus Ponens to draw a conclusion Q, from P and P ⊃ Q. If one questions the legitimacy of this inference and requires us to suggest why Q follows from P and P ⊃ Q, how can we cope with this challenge? Well, a straightforward response is just to say that you must know the fact that Q follows from P and P ⊃ Q in the first place. As Fumerton put it, Carroll’s Tortoise suggests that “having reason to believe A and B by itself won’t force you to the conclusion Z unless you also see the connection between (A and B) and Z.” (Fumerton 2015: 209) But if we add this fact as premise R in our inference, we are also to be asked to suggest why Q follows from P, P ⊃ Q, and R. Consequently, we enter a state of infinite regression.  

Carroll’s Tortoise gives us an opportunity to reconsider the validity of the second clause of the principle of inferential justification. According to Fumerton, the real problem of the astrologer case lies in the fact that such a case is simply an enthymematic argument, not supporting the second clause of the principle of inferential justification at all. It is not clear that how we can distinguish ordinary cases (litmus paper, for instance) and this irrational one (Fumerton 2015: 212-213).

Then, how can we avoid infinite regression and lay claim to use inference legitimately? A sophisticated approach (and I believe this is on the right track) is to distinguish between rules of inference and premises: rules of inference should not be considered the same as premises, for the latter constitutes specific arguments while the former is part of an axiomatic system. Fumerton puts forward this strategy as follows:

“But how do we avoid regress? One straightforward way is to claim that while justified belief in the connecting principle is necessary for justification, the proposition in question should not be treated as a premise. […] the critic will argue that the proposition asserting a connection between premises and conclusion is starting to look and function just like a premise. If it looks like a premise, and epistemically acts like a premise, how do I expect to get away with arguing that it is not a premise? While I concede the objection has initial force, my answer is intended to be disarmingly simple. I read “What the Tortoise said to Achilles” and I don’t want to be in the position of Achilles facing a vicious regress. To avoid Achilles’ fate one simply can’t treat the connecting principle as a premise among other premises.” (Fumerton 2015: 214)

 

References

Fumerton, R. (1995). Metaepistemology and Skepticism. Rowman & Littlefield.

Fumerton, R. (2015). What the internalist should say to the tortoise. Episteme 12 (2):209-217.