13

In conventional medicine, the relevant definition is clinically effective -- basically that there is a statistically significant effect in a suitably controlled (and randomized) test sample. This includes accounting for the placebo effect. If a treatment is clinically effective, that should satisfy the logical positivists. It is not impossible for ...


12

Yes, there is a connection, as you point out. In the Tractatus, Wittgenstein writes: 3.332 No proposition can say anything about itself, because the propositional sign cannot be contained in itself (that is the whole "theory of types"). Gödel, as you know, proceeded to do precisely that. Wittgenstein's argument against type theory is one of many ...


12

Though Popper's critique of the inductive nature of the verification principle was influential, it is the related arguments of Reichenbach, Quine, Hempel, Sellars which most definitively refute verificationism in its Logical Positivist form. Reichenbach, Quine (in Two Dogmas of Empiricism) and Sellars (in Empiricism and the Philosophy of Mind) point out in ...


12

The main element of logical positivism was verificationism. This led to the attitude, that only propositions proven by verification are worth to discuss in philosophy. So metaphysics and ontology had to be ignored according to Vienna circle as they cannot be proved by objective methods. The problem with this view, articulated mainly by Karl Popper, was that ...


8

My reading of Carnap's "The Elimination of Metaphysics Through Logical Analysis of Language" suggests to me that it is possible to form sentences in a language that are grammatically correct but logically meaningless. The consequence of this is that the statement, due to its logical incoherence, cannot be proven to be true or false. And likewise, if a ...


7

What you call "Positivism" there is but a crude description of a principle that has been associated with them. Let's consider a more faithful description of the so-called empiricist criterion of meaningfulness: Criterion. (Hempel 1965b) A sentence makes a cognitively significant assertion, and thus can be said to be either true or false, if and only if ...


7

SEP does a very good job of putting Passmore's claim into context: In 1967 John Passmore reported that: “Logical positivism, then, is dead, or as dead as a philosophical movement ever becomes.” (1967, 57) Earlier in the same article he had equated logical positivism with logical empiricism, so presumably that was dead too. At that time few would have ...


6

The definition of any of these terms is going to be controversial, but your first problem is that your definition of a priori is wrong. The traditional definition is "knowable independent of (any particular) experience". Now, analytic truths (traditionally conceived) are a priori knowable, but just because the analytic truths are a subset of the a priori ...


6

In first order logic: P(x) is has a free variable - x. ∃x P(x) has no free variables, x is bound by the existential operator. This is what is normally called a closed formula or a sentence. Sentences are a key concept in model theory as they allow for well-defined truth values. A set of sentences is called a theory; any individual sentence is a theorem. ...


6

The Logical Positivists did not accept synthetic a priori knowledge. They accepted only Hume's Fork, two kinds of knowledge, as you suggested in the question. Logical Positivism was not a single shared opinion, but a variety of opinions and arguments under a shared general approach. We can take A.J.Ayer's Language, Truth And Logic (1936) as one ...


6

Gödel was a young man in search of a place to belong, many young intellectuals were attracted to the Vienna Circle for its pluralism and tolerance. But it wasn't purely social. Gödel was clearly interested in mathematics, in 1925-26 Schlick, the circle's founder, gave lectures on philosophy of mathematics which Gödel attended. But it was Carnap, who really ...


5

The logical positivists hardly subscribed to verificationism, but your question is about verificationism, not about logical positivists, so that's a minor quibble. Would a statement that is otherwise easily verifiable using empirical means, but is located so far away in space, that a light signal from earth could never reach its location in time to test ...


5

Since I can't search all of Popper's works to see if it is addressed anywhere, I'll give an answer based on a specific work. A minimal answer: In a footnote in The Logic of Scientific Discovery Popper states: "Note that I suggest falsifiability as a criterion of demarcation, but not of meaning." This is in a section where he's discussing positivism. In ...


5

First, one has to make clear which of the many gods is meant. Because theistic people in different religions speak about many different gods: The Olympic gods from the time of Homer, the Egyptian gods, the Vedic gods, the Hinduistic gods, the monotheistic Jewish and Christian god named Jahwe, and many more. Secondly, in Christian theology the attempt to ...


5

Carnap was a comptabilist. From the Carnap's "Philosophical Foundation of Physics" as quoted in the "Cambridge Companion to Carnap" p 303: Free choice is a decision made by some one capable of foreseeing the consequences of alternate action and choosing that which he prefers. There is no contradiction between free choice understood in this way and ...


4

Hume's basic premise is that worthwhile information must contain: abstract reasoning concerning quantity or number experimental reasoning concerning matter of fact and existence When we're talking about abstract reasoning as to quantity or number, we're talking about words and symbols that represent things. The abstraction of a thing is not an actual thing,...


4

No, that is not the question Popper is addressing. Popper was concerned with what was 'scientific' not what was 'true'. I think he is really just defining 'scientific in the normal mode of science'. Other kinds of things still need to be considered 'scientific' as well, even by Popper, on the basis of Popper's own behavior, at least until it can be ...


4

There is boundless faith in second-order logic, because people do not realize that testable second-order theories are almost always really sorted first-order theories in disguise. So science that is not 'spooky' is basically first-order. People in the 1980's were still trying to prove that some second-order theory of the reals was consistent and complete. ...


4

Quoting Wikipedia, ” Carnap envisioned a universal language that could reconstruct mathematics and thereby encode physics.[9] Yet Kurt Gödel's incompleteness theorem showed this impossible except in trivial cases, and Alfred Tarski's undefinability theorem shattered all hopes of reducing mathematics to logic.[9] Thus, a universal language failed to ...


4

This question needs quite a bit of unpacking. For a start, one must distinguish between truth and evidence. To a realist, something may be true without there being any evidence for it. I have no evidence as to whether it rained on Lands End in England at noon on May 1st of the year 1 CE, and I strongly suspect that no such evidence exists or will ever come ...


4

This question largely boils down to a question of definitions -- but these are politically contentious definitions. As such, I want to divide my answer into three parts: (a) difficulties with your definition of philosophy, (b) problematic or questionable interpretative choices regarding the "existentialists", and (c) is existentialism philosophy when these ...


4

Philosophy is a rare field where self-definition is a major topic within the field itself. The definition you proposed and the one you cited have been promoted by those who practice some prominent variants of philosophy. To the extent that they are widely accepted, they appear to affirm those schools of philosophy and delegitimize the others. As you might ...


4

The author you quote seems to be oversimplifying, but it is possible to understand some work of the logical positivists as an attempt at a purely syntactic approach to expressing the relation between evidence and hypothesis. Rudolf Carnap, in particular, attempted to set out a formal logic of induction in which inductive probabilities can be derived from ...


3

There are two dominant ways of looking at what is and is not scientific. Neither of them ever considers any theory 'verifiable'. The kind of truth that has constructive verification is not something science really has access to, perhaps outside of mathematics, and there only by convention. One of them is Kuhn's notion. It focuses on science as a communal ...


3

Philip Kitcher's (1993) The Advancement of Science (Worldcat link) is the account of science I think of as closest to a contemporary version of Logical Empiricism/Positivism. Kitcher might deny that, and certainly his rhetoric in the book suggests he feels he's moved far away from that position. But when it comes down to it, some of us agree that he ends up ...


3

You might be interested in the wikipedia article on Post-Positivist Verificationists. E.g. After the fall of logical positivism, verificationism and empiricism more generally lost many adherents. This trend was stopped and in large part reversed in 1980 with the publication of van Fraassen's The Scientific Image. Constructive empiricism states that (1) ...


3

The difference between the realm of a priori / a posteriori and analytic / synthetic is that that one is an epistemological notion(acquisition of knowledge) and one is a semantical notion (definitions of words). The a priori / a posteriori distinction tells us whether we know something by sitting in our armchair and thinking about it (a priori), or by going ...


3

It is often said that the demise of logical empiricism allowed a renewal of metaphysics in the late 20th century. Kripke (naming and necessity) and Putnam (the meaning of meaning) are often credited for their semantic arguments allowing a renewal of essentialism and realism, i.e. their semantic leaves room for metaphysics. Quine (two dogma of empiricism) ...


Only top voted, non community-wiki answers of a minimum length are eligible