Propositional knowledge

In their excellent introductory text book Modern Epsitemology , Nicholas Everitt and Alec Fisher discuss three kinds of knowledge: capacity knowledge, which is knowledge how to do something; knowledge by acquaintance, which is being acquainted with something or someone; and propositional knowledge, which is knowing that truth or falsity of sentences or propositions. They write (p. 13):

There are clearly some complex interactions between these three types of knowledge.

Good! But then, a paragraph further on, they write:

Historically, it is propositional knowledge which has attracted most attention from philosophers, probably because it connects with such philosophically interesting concepts as rationality and truth (remember that our initial explanation of propositional knowledge was knowledge of truths). We shall follow this tradition and focus on propositional knowledge.

For 'focus on propositional knowlegde', read 'discuss propositional knowledge exclusively'. And yet - may it not be at this preliminary stage that epistemology's subsequent failures are decided? Perhaps the idea of 'propositional knowledge', as something that can be studied in isolation of other kinds of knowledge, is mistaken. And perhaps this mistake is the source of such vexing problems as the inability of philosophers to solve the Gettier problem and the problems of foundationalism.



A first thought, which is pretty natural given certain philosophies of language: propositional knowledge is merely a subset of capacity knowledge. It simply encompasses the capability of saying the right things at the right moment. When someone asks you "What was Napoleon's last battle" and you answer "Waterloo", you demonstrate that you know how to answer this (and related) questions. You also demonstrate that you know the proposition "Napoleon's last battle was Waterloo".

Of course, this analysis is only non-trivial if capacity knowledge of such a kind is based in linguistic practices: if, in other words, truth is analysed as a social concept. And although this may in some cases be a plausible analysis, we still want to say that knowing whether gravitation can be unified with the other forces of nature is something different than knowing how to behave linguistically in certain social situations. We are trying to find that out through physical research, a practice that makes little sense if knowing the truth is merely knowing how to behave correctly.


A second thought. I know what the quickest way is to go to my house from where I am now. This can be interpreted as capacity knowledge: I know how to get to my house as quickly as possible. It can be interpreted as knowledge by acquaintance: I have travelled this route often, and therefore I am acquainted with it. It can also be interpreted as propositional knowledge: I know that the quickest way from my current location to my house is such and so.

Is there a difference between these three things? Is the propositional knowledge any different from the capacity knowledge?

My rabbit knows the quickest way from any point in my room to her cage. Naturally, this means that she has capacity knowledge: she knows how to get to her cage as quickly as possible. But if this knowledge is the same as the propositional knowledge "the quickest way from this point in the room to my cage is ...", then she also has propositional knowledge - even though she cannot talk and probably doesn't think in a linguistic manner.


Let us explore the link between propositional knowledge and capacity knowledge further, by taking the famous Gettier example. Allegedly, Smith knows that "the man who will get the job has ten coins in his pocket". Suppose that we want to identify this with some capacity knowledge. What about: Smith knows that he has to speak to the man who will get the job if he needs ten coins. There may not be identity in a strong sense, but certainly knowing the proposition involves this capacity knowledge. And since capacity knowledge is practical, this means that Smith, unless he is disabled, must be able to actually go and ask the man who will get the job for those coins.

But Smith can't do that! He'll go and ask Jones about those coins, and hey, Jones even has ten coins, but Smith can't go and talk with the guy who'll get the job - because he doesn't know who that is. If we interpret the system of propositional claims as prescriptions for actions, Gettier's example loses its sting.


Does it? This post is too short, and needs a follow up. But I have to go now.