This is a lot longer than I meant it to be, hehe
My main points, which this long, long article attempts to explain, are these:
1. Circular arguments, if they are analytic, can
justify themselves (depending on what you mean by justification...)
2. Hume's argument is one of infinite regress, not circular reasoning, and cannot be broken down into circular reasoning.
3. Hume is not questioning the validity of science, or the external world at large. Rather, he is questioning the validity of it on the grounds of rationalism (deductive, formal logic). Rather, we come to know the world through inductive reasoning, which can be just as valid, though only contingently true. Contingent does not equal invalid.
I am no expert on Hume, however I do believe I see a couple of misinterpretations that you make from him.
If an argument has no support aside from itself, then it is a circular argument.
If an argument is circular, then it has no logical justification.
Past experience has no support aside from itself.
Therefore, past experience is a circular argument.
Therefore, past experience has no logical justification.
First, I do not believe Hume would agree with your second premise here. Instead of "logical" justification, I think it would be more appropriate to use "synthetic" justification. For it is obvious that there are types of circular arguments which can
be logically justified: Relations of Ideas are all circular. The logic behind it is that to contradict such a statement is itself a self-contradiction.
Look at the statement: all triangles have three sides.
The contradiction would be: all triangles do not have three sides.
The contradiction here is a self-contradiction. It cannot be true by definition. This is the importance of Hume (and Kant's) distinction of Matters of Fact and Relations of Ideas. It is not whether or not a statement is a syllogism that makes it a Relation of Ideas, but rather the content of the statement, and whether or not the statement can be contradicted without initiating a self-contradiction.
The logic behind this dates back to Aristotle, and is sound (well, until you get Quine, but then you get into linguistics and Logical Positivism, blah blah blah). But ultimately, Hume would disagree that all circular arguments are logically unjustified - that's the purpose of Relations of Ideas!
Now, onto my second objection: If I may restate your third premise: "past experience has no support aside from past experience."
The bulk of Hume's critique of causality is not a circular one but rather one of infinite regress. I think you make a slight equivocation fallacy in the third premise here in your use of the term "past experience." It is too ambiguous, as it is not circular in the sense that Hume means it.
Let me put it out logically. This is Hume's argument, beginning with your third premise (the first two being irrelevant right now):
My experience at time Z has no support other than my experience at time Y.
My experience at time Y has no support other than my experience at time X.
My experience at time X has no support other than...
The equivocation fallacy comes in because you seem to be using "past experience" first to refer to experience Z, then "past experience" to refer to experience Y. The two are different propositions, and therefore are not circular but rather regress infinitely backwards until memory gives out. Continuing Hume's logic...
My experience at time (N) has no support other than a time [(N)+1]
My experience at time (N) has no support other than an infinite regression of time (N)+1
We cannot know the beginning of an infinite regression.
Therefore, we cannot know the support of any experience at time (N).
Or, even if we wanted to put it in the same terms as your final conclusion, "we cannot know if past experience has any deductive
These two change the outcome of your argument as well. Namely, Hume isn't saying we aren't justified in knowing the world - his claim is that our justification is one of induction rather than deduction. Mostly, Hume's purpose is to yell at the continental philosophers who are trying to rationalize God. He just wants them to realize that you can't know the justification of anything from reason
- only experience
justifies our beliefs.
His entire claim is that our logic from experience IS inductive logic. By definition, inductive logic cannot be deductively justified - otherwise it would no longer be inductive. Hume is arguing that all our knowledge of the world is justified by inductive reasoning.
The last thing I want to point out is mostly about your response to Bill Maxwell. Basically, I think you and Hume are arguing the same point. "It's the fact that their foundation comes from experience which I'm complaining about." This is the same thing Hume is complaining about!!
The fact that everything we know about the world, we know inductively, means that we cannot justify our knowledge of the world by looking towards the formal logic of deduction.
Science for Hume didn't ever "not work." Hume has more faith in natural sciences than philosophy, because natural sciences evaluate the world using inductive reasoning. Hume isn't challenging inductive reasoning per se.
Now let me clarify before everyone goes at my throat.
The challenge here is the difference between necessary truth and contingent truth. The definition of necessary truth is this: any proposition p
in which to attempt to make the claim that ~p
results in a self-contradiction is necessarily true. The definition of contingent truth is anything which is not a necessary truth.
Necessary and Contingent truths correlate with Matters of Fact and Relations of Ideas, as well as the notions of a priori
and a posteriori
. I don't think I need to give a lecture on these two here. However, suffice it to say that deductive logic gives us necessarily true propositions, while inductive logic gives us contingently true propositions.
Hume's skepticism (especially when applied to science) simply questions the validity of such things as being necessary or logically deduced. This does not
imply invalidity through other systems, such as induction. Induction is
valid, but not on the same ground that Deduction is valid. That
is the whole dilemma - science cannot claim that they investigate the world due to deductive methods, and therefore all of science is only true contingently. However, according to Hume, that's the only possible way to do it.
I hope this helps. I've read Hume's Treatise
a number of times, but I am by no means an expert.