Other Opinions #6: Judge Rejects Habeas Petition for Chimpanzee


Disclaimer: I don’t necessarily agree with or endorse everything that I link to. I link to things that are interesting and/or thought-provoking. Caveat lector.


Empiricism and Probability

We have a set of tools now for operating on truths, but we lack the raw materials to operate on. Fortunately there is another common epistemic view.

Empiricism is the view that knowledge of reality comes from the senses. As I mentioned in my brief discussion of axiom #6, we are not assuming quite this much, though we are taking at least a partially empirical view. Our senses provide some sort of access to reality, although that access may be mediated, transformed, inconsistent, etc. Due to this caveat, we cannot simply make knowledge-claims based on our senses: “I see _ therefore I know that _.” could be perfectly wrong.

However, we can say “I see _ therefore I know that something in reality is causing me to see _”. This is somewhat more accurate though less useful. More importantly, we can appeal to the consistency of reality (axiom #3), the partial consistency of memory (axiom #7), and the validity of logic (axiom #8) to make probabilistic empirical claims, such as the following:

I see _, and I have many memories of seeing the same _, therefore it is probable that I will continue to see _.

Of course sight is not the only possible sense here; one can make similar claims using hearing, smell, touch, etc. By adding an appeal to causality (axiom #5) one can also make probabilistic claims about correlation:

I see X and have a memory of just seeing Y. I have many memories of seeing X shortly after seeing Y, and no memories of not seeing X after seeing Y. Therefore it is probable that if I again see Y, I will shortly see X.

(I use X and Y instead of _ above because I have two blanks to fill in that I wish to distinguish between). Just like any probabilistic claim, the more samples you have (in this case memories) the stronger the claim.

It is these probabilistic claims that we can use as raw materials, feeding them into our rational tools to produce an understanding of reality. Of course we cannot use this to achieve whatever constitutes “real” truth with any certainty, but strong probabilities are better than nothing. With rationalism and empiricism in hand we will use the next post to delve more deeply into the concepts of truth and knowledge.

Rationalism and Certainty

The question of what constitutes or defines knowledge is another big problem in philosophy, and on its own forms what is called epistemology. I leave aside (for now) the central epistemic questions in order to discuss certain common perspectives; I will return to the broader questions in a few days.

Rationalism is, loosely defined, the view that knowledge and truth come from reason, logic, etc. By taking axiom #8 we are inherently taking what is at least a partly rational view, although there is somewhat more to it than that. However, on its own this axiom gives us a whole slew of tools in the category of what I shall call “logical systems”. These include propositional and predicate logic, algebra, set theory, probability and all the other systems that are strictly abstract (despite possible practical applications).

The critical point is that these systems are only tools. While they do produce internal “truths” (such as the statement that two plus two is four), all of these internal truths are at root truths by definition. Even the weirder, hard-to-prove theorems do eventually fall out of starting definitions; that’s how we define a proof. More interestingly, these tools give us methods of “lossless” operation on existing truths. The logical form of modus ponens takes two truths and produces a third truth of the same strength; no certainty is lost in the deduction.

These tools are extremely powerful, but like all tools they are useless on their own; they require raw materials to operate on. There are perhaps certain interesting facts that can be derived from our core set of eight axioms, but I would be very surprised if you could get very far (I have not even bothered to try). Instead, we need some other system to generate facts for us to operate on. Next time I will look at where we can get raw materials to feed our rational tools.