Ingvar Johansson wrote:
> Waclaw Kusnierczyk schrieb:
>> Ingvar Johansson wrote:
>>
>>> Being a fallibilist means
>>> to accept that a theory may be empiricially adequate for a time without
>>> being completely true. I think what (reading vQ:s mail) might be
>>> pedagogically missing in Peirce and Sowa is a concept advertised by
>>> another fallibilist, Karl Popper. He verbalizes it using three different
>>> expressions: ‘truthlikeness’, ‘verisimilitude’, and ‘approximation to
>>> truth’. Theories are not just either true or false; truth can take
>>> degrees. And very very much tells in favor of the view that most
>>> empirically adequate theories have a rather high degree of truthlikeness.
>>>
>> i am not sure how much to like the 'partially true' and 'truth can take
>> degrees' parts.
>>
>> clearly, if we think of a theory as of a set of statements, the theory
>> is partially true if there is a subset of it with every statement being
>> true. (every theory is partially true, since every theory includes the
>> empty theory, which is vacuously true.)
>>
>
> This is *not* what I mean. The intuition behind the notion of
> 'truthlikeness' can be explained in the following way.
>
> Assume that the statement (1) "The sun is shining from a completely blue
> sky" is simply true. Look then at the statements (2) "It is somewhat
> cloudy" and (3) "It is raining". I would in this situation say that (2)
> is *more truthlike* than (3).
>
> Another case. Assume that the statement (1') "There are four blood
> groups plus the Rh factor" is simply true. Look then at the statements
> (2') "There are four blood groups" and (3') "All blood has the same
> chemical composition". I would in this situation sa that (2') is *more
> truthlike* than (3').
>
> The fact that we can never know with *absolute certainty* that (1) and
> (1') are true does not make the notion of 'truthlikeness' semantically
> incoherent.
> (01)
I would think that, irrespectively of (1) being true or false (in the
sense of its correctly describing the state of the matters, as in some
flavour of the correspondence theory of truth), any of (2) and (3) is
either true or false. Their truthlikeness is not really a measure of
how much they are true, but rather of how much we certain that they (or
the initial assumption) are or are not true. (02)
If we assume that (1) is simply (?) true, then both (2) and (3) must be
(simply?) false to us. That (2) appears more truthlike than (3) to you
reflects your uncertainty about how accurate (1) is. (Not 'how true (1)
is'.) (03)
If I am sure that (1) is true, then (2) and (3) are equally truthlike to
me, in that I am sure that both (2) and (3) are false. This is of
course completely irrespective of whether any of (1), (2), (3) is true. (04)
But if I have any doubt in (1), then (2) and (3) should appear at least
plausible to me. And, as far as my experience reaches, the situations
in which it is raining are only some of the situations in which it is
cloudy, and all situations in which it is raining are situations in
which it is cloudy (leave exceptions aside). So yes, (2) appears more
truthlike than (3) to me, but this is only in virtue of my doubt about
(1)s truth, and irrespectively of the truth; either (1) or (2) are
true, but not both, and none of them is 'partially true'. (05)
Another thing is how likely it is that, given that the sky is completely
blue, it won't be completely blue in a few moments. So you could say
that, given (1) is true, it is more likely that (2) will soon be true
than it is for (3). I would expect that becomes cloudy before it begins
to rain, and that it may get cloudy and not raining, but not the other
way round. So, given (1), (2) is more truthlikely to me; but still,
either (1) or (2) is true now, and either (1) or (2) will be true later. (06)
Given a statement s, we should keep separate the truthness of s (s is
either true or not) and our confidence in that s is true (here you may
have degrees). I agree that talking about truthlikeness may be very
useful, but it is not talking about truth. (07)
(In the case of (1') and the rest, I would rather subscribe to (3').) (08)
vQ (09)
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