PHIL 0610 Philosophy and Science Handout #3
Hello, dear friend, you can consult us at any time if you have any questions, add WeChat: daixieit
PHIL 0610
Philosophy and Science
Handout #3
Objections to logical positivism
I. Verificationist principles
Recall from earlier: The criterion of verifiability: A sentence is factually significant to any given person if and only if that person knows how to verify the proposition which it purports to express. Ayer asserted that sentence is literally significant if it is factually significant or it is a tautology (i.e. an analytic truth).
The logical positivists struggled to successfully formulate any version of a verificationist principle that would do what they wanted of it. In particular, it turned out to be very difficult to formulate the principle in a way that would exclude the metaphysical claims the logical positivists wanted to reject, but keep all the science that they wanted to preserve. For reasons to do with how things work in logic that we won’t be getting into, it was shown that anything at all would count as meaningful according to Ayer’s verificationist principle if it was combined with other claims in the right way. E.g., The sentence “metals expand when heated and the Absolute is perfect.”
II. Other problems with verificationism
Some of the objections Godfrey-Smith discusses in our reading for today come from the philosopher Willard Van Orman Quine’s 1951 paper “Two dogmas of empiricism.” Quine was an American philosopher from Akron, Ohio. He remains very influential amongst contemporary analytic philosophers. He met Carnap and other members of the Vienna Circle and Ayer while traveling in Europe in the early 1930s. He also had philosophical discussions and written correspondence with Carnap after the latter moved to America in 1935.
In “Two dogmas of empiricism,” Quine attacks two parts of Ayer’s view:
1. The idea that there is a clear distinction between analytic and synthetic sentences.
2. The idea that there are observations that would allow us to determine whether a single claim is true or false.
Ayer’s criterion of verification suggests that it is possible to verify a single claim. But Quine thinks that this is a false assumption. When we try to test one claim through experience, we can’t help but make a lot of other assumptions at the same time. For example, I might need to make assumptions about measuring equipment, the reliability of written records, etc. While we might think of ourselves as testing a single claim, we are actually testing something like the single claim + the reliability of our measuring equipment + the reliability of written records +
… .
Quine’s objection is not against the idea of verificationism, his objection is directed toward the size of the unit of thing we are attempting to verify. Quine says: “our statements about the external world face the tribunal of sense experience not individually but only as a corporate body” (p.41).
III. Holism about testing
Quine’s alternative proposal is holism. Holism about testing says that
we can’t test a single sentence in isolation. Quine thinks that the totality
of our beliefs about the world are like a piece of fabric. When our web
of beliefs comes in conflict with our experience, we make adjustments
to certain of our beliefs, and since our beliefs are interconnected, these
changes are going to have effects on other beliefs. In this picture, all
beliefs are revisable (even the ones Ayer thinks of as analytic). However,
there are certain beliefs that we are much more reluctant to change Figure 1 From Ney, A. (2014) Metaphysics: an introduction, Routledge, p.130
than others.
Godfrey-Smith notes that the philosophical community generally considered Quine’s objection here fatal to the project of logical positivism. He argues that this might not have been a fair response, since the logical positivists themselves seemed to endorse holism about testing. Godfrey-Smith’s conclusion is that thought the logical positivists did officially accept a holistic view about testing, they did not fully appreciate the significance of the point.
IV. The analytic-synthetic distinction
Ayer distinguishes between statements about the world and the statements of logic and mathematics. Recall from last class the distinction between analytic and synthetic sentences. Analytic sentences are those that are true or false just in virtue of the meanings of the words in the sentence. For example, the sentence “all bachelors are unmarried” is true in virtue of the meanings of the words in the sentence. Synthetic sentences are those that are true or false not just in virtue of the meanings of the words in the sentence. The sentence “all bachelors have a beard” is an example of a synthetic sentence. Whether it is true or false depends on how the world is and not just the meanings of the words.
According to Ayer, all of mathematics is composed of analytic sentences. Any claim in mathematics, according to this way of thinking, trades on the meanings of the terms involved and is thus empty of content relating to the world.
This distinction between analytic and synthetic sentence was taken for granted by philosophers for a very long time. But Quine argues that this is a very long held confusion about these concepts. Quine thinks there is no sharp distinction between analytic and synthetic sentences.
In “Two dogmas of empiricism,” Quine considers various ways we might try to draw this boundary and argues that none of the methods he tries quite works. So, he concludes that it isn’t possible to draw a clear boundary between analytic and synthetic statements. You might worry that Quine’s conclusion is drawn a little too quickly. Quine considers a few ways to draw the analytic-synthetic distinction and when each of these methods fail, he concludes that there is no way to draw the distinction. That seems a bit too quick! But Quine has other reasons for thinking there is a problem. Quine thinks that whether a sentence is true depends on what its words mean and how the world is. Analytic sentences are supposedly true only because of what the words mean, not how the world is. But Quine doubts that these two contributions can be neatly divided.
V. Hidden structures
Remember that Ayer objected to the view that philosophy involved obtaining knowledge of a transcendent reality. We can think of the logical positivist project as denying that behind the ordinary world of observables there is a special and mysterious realm that is only knowable indirectly. Godfrey-Smith calls this a “layered” view of reality. The logical positivists were (maybe rightly) suspicious of this kind of view. They conceived of science as merely describing the observables and denied that there were mysterious hidden structures that gave rise to these observable phenomena. The trouble is that science really does seem to be an attempt to describe hidden structures that give rise to observable phenomena. The logical positivists insistence that there are only surface-level observations to be made, not attempts to understand hidden phenomena, is at odds with what goes on in science.
VI. A final problem for verificationism
A recurring worry for verificationism is that it is self-refuting. Any statement of the verification principle is not itself a tautology, nor is it verifiable through experience. Therefore, it seems that by its own criteria, the verification principle is itself meaningless. The logical positivists were aware of this problem. Carnap accepted that the principle is strictly meaningless, but he thought that it is still a useful recommendation. According to Ayer and Carnap, a statement like “murder is wrong” is also meaningless or lacking in factual content, but neither thinks that this means that we would thereby be in the clear to start killing each other. Ayer thought that statements like “murder is wrong” are expressions of emotion and so it really means something like “Boo murder!” . We can interpret the logical positivists as asserting “Hooray verificationism!” when they recommend a verification principle. But how is something like that supposed to be persuasive?
2023-02-18
Objections to logical positivism