There's a tendency because, a similar tendency in all, you know, all the arts and humanities,
maybe a little bit in science too, except the more experimental the science is the more
of a corrective there is on swinging to extremes, but the.
What I have in mind is that when a school goes out of fashion it's as if it had no insights
at all and the result of that is that errors that that school very clearly pointed out
and explained why they are errors then get repeated because you don't read those people
anymore and you also don't read what was right.
So and examples are, I think, extremely common.
I think the, the doubtless the rationalists threw out many of the insights of the empiricsts.
But also the Kant.
I mean, it's interesting.
In 19- Let me go back to my teacher Hans Reichenbach.
My favorite book of Reichenbach's is a book he wrote in 1921, published in 1921, called
relativity theory and a priori knowledge.
And people call that, sometimes people say well he was a Kantian or still a neo-Kantian.
Well he wasn't a neo-Kantian in the technical sense but it's clear that at stage he saw
that there were insights in Kant that one needed to preserve.
And I think those were the ones that he forgot later in his writings, his later writings
on relativity theory.
Especially in the fin—the Rise of Scientific Philosophy.
But he saw the problem, the question of that book, Relativity Theory and a Priori Knowledge
is just the question that Thomas Kuhn claimed the positivists, the logical empiricists never
saw, namely how are scientific revolutions possible.
Reichenbach doesn't use the terms scientific revolution, but he has a distinction between
framework principles in science and ordinary empirical statements.
I had to rediscover that for myself or reconst -- myself many years later because the Reichenbach
I studied with was teaching the Rise of Scientific Philosophy and that's totally disappeared.
But at that period, so many years later when I went back and read the 1921 book, sort of,
"My God!"
Here he sees that you can—every observation report in the age of Newtonian physics was
couched in the vocabulary of Newtonian physics.
So the question is when the observations themselves are loaded with a theory, with a framework,
how can that framework be rationally revised.
Unlike Kuhn, Reichenbach included that it could be and gave a very interesting answer.
He answered, yes, relativity theory and Newtonian physics have different framework principles,
but they agree on certain things.
For example they agree in their description of what the telescope does.
So you can.
There is a class of observations that they can both agree are relevant to certain questions
that do the, is this line straight or not straight.
Do these lines meet or not meet.
And that's what you need to make possible a rational test of a proposed new framework
and it's a brilliant answer, which Kuhn does not consider.
But the important thing about it is he sees the need for this notion.
In a paper he wrote in 1922, in which he praises Cassierer as the only German philosopher,
other than himself who really understand relativity theory, he says we need, but he doesn't agree
with Cassierer that we need to preserve some synthetic a priori.
He says we need a revisable synthetic a priori.
But later on, but then Carnap didn't like that.
I mean, Michael Friedman who has noticed this too and written about it, investigated it,
tells me that it's really the influence of Carnap that pushed Reichenbach to a more positivist
position.
So then Carnap really wanted throw out the bathwater, throw out the baby, not only the
bathwater and eventually succeeded in getting Reichenbach to throw out the baby, the baby
being here that we can't, that not all physical statements follow on a par.
Some of them constitute the very lenses through which you see physical phenomena.
And that's a Kantian idea.
Kant put it in the structure of the mind after the linguistic turn we say certain things
are in the very structure of the language at a given time are like lenses through which
you see the phenomena.
They're partly constitutive of the phenomena.
So, and I think, in almost every area of philosophy you can see how when a movement goes...now
we have a rediscovery of by Chris Korsgaard, Barbara Herman and others, all students of
John Rawls, of insights in Kant's ethics.
Which for a long time was just dismissed in half a page.
Well, there are what I have, I'm still struggling for a name for this.
I used to call these principles, you know, a priori relative to a body of knowledge or
contextually a priori, but relative to a body of knowledge.
I don't like that because they can be fal—they're false so how can you call something a priori
which turns out to be false, but there are, I think, things which are quasi-, I've fallen
on quasi-necessary.
There are statements which are quasi-necessary at a given time relative to the given body
of knowledge of that time.
And that's the, that I think is the insight that in the limited area of physics Reichenbach
had in the 1921 book.
It's an insight.
It really—it means that when, as he did then, one attempts to ask was Kant onto something.
Maybe he misdescribed it but has he noticed something here?
That we should be paying attention to.
Rather than, you know, Kant is obsolete.