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Verificationism. Classical Empiricism. Last time we learned about the idea theory. Although it wasn’t confined to the empiricists, most of them ascribed to it (Locke, Berkeley, and Hume being the most notable). Classical Empiricism.
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Classical Empiricism Last time we learned about the idea theory. Although it wasn’t confined to the empiricists, most of them ascribed to it (Locke, Berkeley, and Hume being the most notable).
Classical Empiricism Empiricism was variously the doctrine that all ideas “came from” experience, or that all knowledge did, or both. (Usually both.)
Classical Empricism Empiricism had its problems, in addition to those that the idea theory suffered from: Modal Knowledge: Experience tells you what is, not what must be/ should be/ will be. Yet we can know some of these things.
Classical Empricism Empiricism had its problems, in addition to those that the idea theory suffered from: Poverty of the Stimulus: We figure out things like language use faster than experience is capable of teaching us. This suggests innateness.
Positivism The French philosopher/ first Western sociologist Isidore Auguste Marie François Xavier Comte (1798-1857) theorized that society progressed in three stages: from the theological, to the metaphysical, to the “positive.”
Theological Stage In the theological stage, people believe any silly or magical thing their ancestors attributed to the gods.
Metaphysical Stage Next, in the metaphysical stage gods go out of the picture, but are replaced with unjustified “metaphysical” assumptions (e.g. universal human rights).
Positivism Finally, in the positive stage, the truth of our beliefs is “positively” determined. Compte thought science was the only source of positive determination.
Logical Positivism Around the 1920’s in Vienna and Berlin certain philosophical doctrines became popular, and their adherents were variously known as Logical Empiricists or Logical Positivists (sometimes neo-Positivists).
Empiricist Criterion of Cognitive Significance According to the logical positivists, in order for a sentence to have cognitive significance (to be meaningful), it had to have verification conditions.
Empiricist Criterion of Cognitive Significance ‘Verification’ is a Latinate English word < ‘veri-’ true + ‘facere’ to make. Verification conditions are conditions under which the truth of a statement can be conclusively established.
Empiricist Criterion of Cognitive Significance In fact, the positivists maintained that the meaning of a sentence was its verification conditions. So a sentence with no verification conditions– where no experience can establish its truth– is meaningless.
Truth vs. Verification Many philosophers (even today) have identified the meaning of a sentence with its truth conditions. These are the circumstances in which the sentence would be true. But the positivists went farther– they held that the meaning of a sentence was its verification conditions– the circumstances in which we would know the sentence was true.
The Elimination of Metaphysics This was part of a radical philosophical agenda, which included “the elimination of metaphysics.” The idea was to view many philosophical problems of the past (and also many religious claims) as meaningless disputes that could simply be ignored.
Anti-Religion Example: In a religion where God is beyond human experience, the positivists would say that “God exists” is neither true nor false but meaningless, since no experience could verify it.
Anti-Metaphysics Kant, Hegel, and Heidegger were also big targets for the positivists. Example Hegel quote: “But the other side of its Becoming, History, is a conscious, self-meditating process — Spirit emptied out into Time.”
The Elimination of Metaphysics The positivists even wanted to eliminate a lot of more down-to-Earth metaphysics: Modality: We can only experience what is, not what could possibly be. So statements about what is (merely) possible are meaningless. Normativity: We can only experience what is, not what should morally be. So statements about what is good or bad are meaningless.
Metaphysics! Metaphysics! One positivist, Otto Neurath, would shout down speakers with “Metaphysics! Metaphysics!” when he thought they were saying something that couldn’t be verified.
The New Science There was also a scientific impetus to logical positivism (beyond the just pro-science message of positivism). Kant influentially held that Euclidean geometry was synthetic a priori, and that our experience must be as of a Euclidean spacetime. But the Minkowskispacetime in relativity is non-Euclidean.
Einstein How do you respond to opponents (classical physics) that think their theory is knowable in advance of any argument or evidence? Einstein responded by operationalizing: imagining rigid rods extending in all directions, and clocks at various points. That is, his arguments were couched in terms of what you could measure or experience (rather than straightforwardly in terms of what was true).
Quantum Mechanics Quantum mechanics also had metaphysical problems of its own. Several counterintuitive experiments seemed to suggest that the basic laws of the universe were not quite consistent with the laws of logic.
Quantum Mechanics This led some physicists to simply deny that there were questions to be answered beyond “what do we observe/ experience?”– no questions like “what is the reality causing the appearances?”
Empiricist Semantics According to the positivists, the elimination of metaphysics followed from the correct account of meaning. When we understood that meaning = verification conditions, then we would see that ‘the Absolute is perfect’ or ‘God exists’ can’t possibly have meanings. Then we would be free to look into more promising, resolvable philosophical questions.
Observation Sentences We single out a certain, small set of sentences to be the “protocol” or “observation” sentences. These sentences are all very simple syntactically, along the lines of: ‘that is red.’
Immediate Experience RED LOUD PAIN THREE
Middle-Sized Objects TABLE DOG CHAIR MOUNTAIN
Observation Sentences The importance of the observation sentences is that they can be immediately verified. To tell whether ‘that is red’ is verified (is true), you just have to look.
Non-Observation Sentences All the other meaningful sentences (according to the verificationist) are defined in terms of the protocol sentences and the logical vocabulary (AND, OR, NOT, ALL, SOME, NO, etc.).
Definition of ‘Arthropod’ For example ‘That is an arthropod’ := That is an animal AND it has a jointed body AND it has segmented legs.
Non-Observation Sentences Obviously these sorts of definitions work best with scientific terminology like ‘arthropod,’ but the positivists were happy with that. It could turn out that much of our ordinary talk was not strictly speaking meaningful, but needed to be regimented in a more scientific language.
ObservationSentences There was some measure of debate among the positivists regarding which sentences actually qualified as observation sentences. The simpler the qualities they are about (e.g. ‘that is red’ ‘that is warm’ ‘this is joy’) the easier it is to argue that they can be verified immediately, but the harder it is to define the rest of the sentences.
Observation Sentences Try defining “CY Leung is the chief executive of Hong Kong” in terms of what things are red, warm, joy, etc.!
ObservationSentences On the other hand, it’s easier to define more abstract things if we let sentences like ‘That is a chair’ or ‘That is a person’ be observation sentences. However, can these things really be immediately verified?
Our observations don’t seem to guarantee that something is a gorilla (it might be a man in a costume, or the reflection of a gorilla, or…)
The Aufbau In the Aufbau (The Logical Structure of the World), Carnap undertook an ambitious project to outline how one could translate all “high-level” talk (e.g. “the train to Vienna is running late”) into talk about sensations at coordinate points in the visual field (“quality q is at point-instant x;y;z;t”
Verificationist Semantics So here’s the picture: #1. The meaning of a sentence is the set of experiences that would verify it.
Verificationist Semantics #2. Observation sentences are directly connected with their verification conditions: we can immediately tell whether they are verified in any particular circumstance.
Verificationist Semantics #3. Non-observation sentences inherit their verification conditions from the pobservationsentences they are logically constructed out of.
Special Exception One exception was made: logic and mathematics were held to be meaningful, even though its hard to state (for example) what experiences would confirm “2 + 2 = 4.”
Costructivism Constructivism was a positivist-influenced, non-classical approach to logic and mathematics that said that only provable formulas (only “mathematically verifiable” formulas) were true (denial of excluded middle).
