Justified true belief: knowledge and the myth of propositions

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Re: Justified true belief: knowledge and the myth of propositions

Post by Londoner » Thu Aug 03, 2017 9:33 am

Peter Holmes wrote:
Wed Aug 02, 2017 8:19 pm
Thanks. I'm afraid I disagree with all of this, partly for the reasons in my OP, which you don't address. You're explaining Descartes' theological motivation, but only by repeating his unjustified assertions. An argument is not evidence, and there is no evidence for an idea of a god 'that is already present in the mind'. This is reminiscent of the 'sensus divinitatis' that Plantinga falls back on - or of the ontological argument - or even of presuppositionalism. My position is that theism is irrational, so I don't suppose we can pursue this discussion to much purpose. But again, thanks.
You asked, of Descartes; Why do you say experiences are the only certain thing in his view? I explained Descartes position. If you disagree with what I wrote then that would be about whether I have given a true account of what Descartes said. Whether Descartes was correct is a different matter. I did not say he was.

That said, I think your objection is a bit odd. Descartes' argument refers back to Plato.

Regarding your other posts, I think I agree with much of what you write, but I had problems when you got to:
As you say, we establish the truth of 'the earth orbits the sun' by means of evidence. And I think this is an objective truth, independent of any belief or knowledge-claim, which the JTB truth condition acknowledges: S knows that p only if p is true. But no evidence that I'm aware of can establish the truth of 'a=a' or '2+2=4'. They are tautologies, so only vacuously true - reliable only because they are unfalsifiably correct and tell us nothing about reality - though we use them to say falsifiable things about features of reality.
I disagree that we do establish the truth of 'the earth orbits the sun' by means of evidence. That claim is also a tautology, in that it must follow from that evidence, however the evidence would also need to be established. And the evidence for the evidence, and so on. In the end, that 'truth' must either rest on something that we do not know to be true - in which case its truth is not 'established'. Or it must be circular, the 'truth' of the claim guarantees the truth of the evidence - and vice-versa.
My point is that inductive inference - where the premise(s) give us more or less convincing reasons to accept the conclusion, but don't entail the conclusion - is not the best that we can hope for when it comes to our empirical knowledge of reality. We can have objective knowledge of reality, expressed by factual assertions such as 'the earth orbits the sun', which can then be true premises in valid deductions with entailed conclusions. We aren't stuck with always insecure knowledge of reality. The problem of induction - that the future need not be like the past - doesn't affect the way things are now: the earth does orbit the sun - from which we can deduce true conclusions.
There, I do not understand where 'inductive inference' comes in. I understand 'induction' to involve inferences from the particular to the general. That step is a use we make of empirical knowledge, but it is not itself empirical. That (say) 'the future will be like the past' is a metaphysical claim. Perhaps you also think this, it doesn't seem entirely clear.

And in the first post:
There are features of reality; there is what we believe or know about them, such as that they are the case; and there is what we say about them, which may be true or false. To muddle these things up is a mistake.
I think they are always necessarily muddled. We cannot separate a 'features of reality' from 'what we say about them' (or 'think about them' would be better). First assuming there is a particular thing; 'reality', I can only encounter that 'reality' via my own mind and I can only express what is in my mind via language.

Discussions of what we mean by 'knowledge' or 'belief' have to operate within the muddle. It is no good constructing a definition of those words that refers to something external like 'objective knowledge' (the words used in your previous paragraph in the OP) because we never have it.

Peter Holmes
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Re: Justified true belief: knowledge and the myth of propositions

Post by Peter Holmes » Thu Aug 03, 2017 10:08 am

Thanks, Londoner. That's very useful and interesting. I have several questions about what you say that I need time to formulate - but I have to take a break for a while. Just wanted you to know I'm grateful for the time and care you've taken, and I hope to respond in time.

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