I need not refute that. It's irrelevant — creativesoul
Srap wrote:
The only belief he attributes the Smith is the belief that p v q; he seems purposefully to avoid attributing p, which will turn out to be false anyway. Gettier only relies on p for justification, not for truth.
I assume everyone who accepts the JTB account of knowledge feels the same way, else having both justification and truth would be redundant. — Michael
p3. ((p v q) is true if...(insert belief statement(s) regarding what makes this particular disjunction true)) — creativesoul
Sure. But we know that what Smith thinks is a good reason for believing p v q is actually a very bad reason - it is false.
So although Smith thinks he has a justified true belief, and hence knows that p v q, he is wrong because the justification is false. — Banno
Having both justification and truth is far from redundant. — Banno
Modus Ponens cannot account for disjunction. — creativesoul
Gettier states:
I shall begin by noting two points. First, in that sense of "justified" in which S's being justified in believing P is a necessary condition of S's knowing that P, it is possible for a person to be justified in believing a proposition that is in fact false.
Secondly, for any proposition P, if S is justified in believing P, and P entails Q, and S deduces Q from P and accepts Q as a result of this deduction, then S is justified in believing Q.
Keeping these two points in mind I shall now present two cases in which the conditions stated in (a) are true for some proposition, though it is at the same time false that the person in question knows that proposition.
Gettier wrote:
Let us suppose that Smith has strong evidence for the following proposition:
(f) Jones owns a Ford.
Smith's evidence might be that Jones has at all times in the past within Smith's memory owned a car, and always a Ford, and that Jones has just offered Smith a ride while driving a Ford. Let us imagine, now, that Smith has another friend, Brown, of whose whereabouts he is totally ignorant. Smith selects three placenames quite at random and constructs the following three propositions:
(g) Either Jones owns a Ford, or Brown is in Boston.
(h) Either Jones owns a Ford, or Brown is in Barcelona.
(i) Either Jones owns a Ford, or Brown is in Brest-Litovsk.
Each of these propositions is entailed by (f). Imagine that Smith realizes the entailment of each of these propositions he has constructed by (0, and proceeds to accept (g), (h), and (i) on the basis of (f). Smith has correctly inferred (g), (h), and (i) from a proposition for which he has strong evidence...
Gettier wrote:
S is justified in believing P, and P entails Q, and S deduces Q from P and accepts Q as a result of this deduction...
Gettier:
...Smith is therefore completely justified in believing each of these three propositions...
...S is justified in believing Q.
Modus ponens cannot account for the thought/belief process required for arriving at believing Q when Q is a disjunction deduced from P. — creativesoul
4. Logical implication is a justification. — unenlightened
inference is not expected to confer truth, but to preserve it. — Srap Tasmaner
Get involved in philosophical discussions about knowledge, truth, language, consciousness, science, politics, religion, logic and mathematics, art, history, and lots more. No ads, no clutter, and very little agreement — just fascinating conversations.