JTB+ and the first person perspective
I have already expanded a bit on certain problematic aspects of the JTB+ theory. In this essay I will expand on a certain methodological feature: If you're "looking" from the 1. person perspective, then there is little or no difference between justified belief and knowledge.
Just to recap, JTB+ is a theory of what knowledge is. JTB+ claims that knowledge consists of at least four jointly necessary and sufficient conditions:
JTB+. S knows that p iff 1. S believes that p. 2. S is justified in believing that p. 3. p is true. 4. [It is not a Gettier case]
I have assumed that JTB+ is true, that is, that JTB+ adequately captures what knowledge is; is a proper account of knowledge.
I have also assumed that there is no difference in the level of justification between justified belief and knowledge, that is, the same level or strength of justification is needed to be justified in a belief and to know a belief if the other conditions also apply (i.e. the believed proposition is true and it is not a Gettier case.).
Let's look at the JTB+ set of conditions from then 1. person perspective. This is done by adding 'S believes that...' to the 4 conditions above:
JTB+ 1. person. S believes that S knows that p iff: 1a. S believes that S believes that p. 2a. S believes that S is justified in believing that p. 3a. S believes p is true. 4a. S believes that [It is not a Gettier case]
Most philosophers agree that one has some sort of special ability to (perhaps infallible) tell what oneself believes. And so if S believes that S believes that p, then it (reasonably; arguably) follows that S believes that p. In other words: (1a) implies (1).
Interestingly, (3a) implies (2a) given that one is epistemically rational. By epistemic rationality I mean that one only believes something if one is epistemically justified in doing so. This is contrasted with another form of rationality called pragmatic rationality which, roughly, goes like this: One believes that p if believing p is good for one. With 'good for' I mean something like: makes one happy. When I write 'justified' I mean 'epistemically justified'.
Also it is assumed that one is not irrational, that is, believing things without any justification at all.
Remember that believing in p is logically equivalent to believing that p is true. This is what it means to believe in p.
Then, assuming the person in question is epistemically rational, then it follows that (3a) implies (2a). Also interestingly, (2a) implies (3a). This is because, at least generally speaking, if one believes that p and p implies q, then one believes that q. In other words: If one has justification to believe something, then one believes it. Beginning to believe that p is, at least generally speaking, an automatic process resulting from the belief that one is epistemically justified in believing p. There is, broadly speaking, no choice involved. This denies a view about belief formation that is called voluntarism.1 Quoting philosopher Theodore M. Drange:
Sobel assumes the voluntarist outlook that it makes sense to speak literally of "choosing to believe or not to believe." I myself have strong misgivings about such an outlook. It does not seem to me that such an action is performed frequently or that it is performed by psychologically normal people. Rather, I find that normal people usually just believe automatically in accord with their assessment of the evidence available to them, and do not make choices to believe or not to believe.2
So, since (3a) implies (2a) and (2a) implies (3a), then they are logically equivalent. This implies that from the 1. person perspective truth and justification are conflated or equivocated given the premises and assumptions I have mentioned.
Does this establish the thesis I mentioned in the beginning? Almost. There is still a (perhaps set of) anti-Gettier case conditions to be met.
1However, this term is also used for other things.
2Taken from Theodore M. Drange, Review of Jordan Howard Sobel's Logic and Theism, 2006; http://www.infidels.org/library/modern/theodore_drange/sobel.html