Two Dogmas of Empiricism

Two dogmas of empiricism ( Original title: " Two Dogmas of Empiricism " ) is one of the most important essays of the American philosopher Willard Van Orman Quine, thus also one of the most important essays of Analytic Philosophy. He first appeared in 1951 in the journal " Philosophical Review ", then later in the anthology "From a logical point of view " ( " From A Logical Point of View", 1953).


The two of Quine attacked " dogma " of empiricism are:

  • The epistemological reductionism. This states that a theory can be broken down into individual statements that could ever be empirically tested for themselves.
  • The distinction between analytic and synthetic statements. It says after discussing the situation in the former analytical philosophy that the truth of some sentences ( analytical ) results solely by the sub-expressions used in them, whereas the truth of the other sets ( synthetic ) resulting from their agreement with reality.

Section 1: Background for Analyticity

To distinguish " analytic / synthetic ", which goes back to Leibniz, Hume and Kant, Quine, Quine serve the following sentences as an example:

  • All bachelors are unmarried.
  • All living beings, who have a heart, have kidney.

Both sentences are true, but between their truth, it seems, an important difference: The first sentence is true only because of the meaning of the words involved, especially because " bachelor " " unmarried man " means. The second sentence is true based on empirical facts, ie, that it is true, could not be found just by thinking about the meaning of the words "heart ", " kidney" and " being", but only through a scientific investigation.

Quine it comes to emphasize this distinction intuitively plausible as unfounded. His strategy for this is rather indirect: He examines a number of ways to explicate this distinction, and shows that each of these possibilities misses the target.

First, Quine turns out the close connection between analyticity and synonymy: An analytic statement can be turned into a logical truth by synonymous terms are replaced for each other. For example, the analytic set

In the logical truth

Be translated by the term " bachelor " is replaced by synonymous with him, " unmarried man ". Because of this close relationship to Quine's critique is directed against both the notion of analyticity as well as against the synonymy. He studied in the following a number of ways to resolve one of these two terms.

Section 2: Definition

The explanation here is that terms are synonymous due to a definition, ie that " bachelor " is defined as " unmarried man ". Quine's answer is that a definition, for example, to is in a dictionary to be correct, already based on a previous language use must and therefore can not be considered due to the synonymy.

Section 3: substitutability

Another possibility is to say that synonymous expressions are irreplaceable for each other in all contexts. " Bachelor " and " unmarried man " therefore are therefore synonymous, because they " are Necessarily all bachelors bachelors " of the sentence may proceed to " Necessarily all bachelors are unmarried ". Quine points out, however, that this test can only distinguish analytic truths of merely empirical truths such as " All living beings are creatures with kidneys with heart " when the substitution into opaque contexts takes place in, ie the sentences in which is replaced, already intensional adverbs such as "necessary" included. However, these expressions are only understandable if one presupposes an understanding of the term " analytical", the need to clarify it.

Section 4: Semantic Rules

In formal systems, the analyticity of natural languages ​​over so-called " semantic rules" ( sometimes called " meaning postulates " ) are modeled. According to Quine, this phenomenon appears, however, as this irreducible fact - on the relevant for it " mental, behavioral or cultural factors " ( "mental or behavioral or cultural factors" ) are not addressed. It is a too strong simplifizierendes model that has no explanatory value for the present problem.

Section 5: Verificationism and reductionism

The last examined by Quine 's proposal to clarify the concept of synonymy is: Two statements are synonymous if they have the same empirical verification conditions. An example of the term " verification condition": The sentence " The objects A and B are of equal weight " could have the following verification condition: " If A and B sets on the two sides of a balance scale, this aligns horizontally ".

In the case of a " radical reductionist " empiricism, the verification conditions themselves must turn in statements about " sense-data ", ie, translate direct experience. Such statements might look something like this: "I have here and now a red - sensation ".

Rudolf Carnap, " The logical structure of the world" in his book tries to perform such a reduction. However, according to Quine, he's failed before, he himself had his project viewed as a failure, because he had never represented again in his later publications such reductionism.

At this point shows how the two of Quine criticized dogmas, the existence of analytic sets and the reduction to the meaning experience related: Quine says that both are based on the same idea, namely that split the truth of a sentence in a linguistic and a factual component could ( "that the truth of a statement is somehow analyzable into a linguistic component and a factual component" ). Two sets with the same linguistic component are interchangeably in the case of an analytical record the actual component is zero. The factual component must be identified by the reductionist idea with the confirmation by sensory experience.

The reason why this idea is wrong according to Quine, is the following: It is based on that empirical confirmation and refutation takes place at the level of sentences, ie that there are phrases that are classified as true or false in the face of sensory experiences. According to Quine, but not individual sentences are confirmed or refuted, but groups of sentences, ie whole theories. Sentences about the outside world stood not alone before the tribunal of sense experience, but together ("My counter suggestion [ ... ] is did our statements about the external world face the tribunal of sense experience not Individually but only as a corporate body" ). Quine points out that before him Pierre Duhem has formulated a similar thought, the view is therefore also known as the Duhem - Quine thesis.

Section 6: empiricism without dogmas

In the sixth and final section presents Quine a counter-proposal to the empiricism with the two dogmas ago. He dresses this design in a vivid picture: According to this picture, the totality of the scientifically recognized movements forming a net-like, spherical structure. Along the periphery of this ball the sentences that deal with sensory experiences, nearer the center are sentences, have the basic legalities of the subject, just as the laws of physics, and even further inside, the laws of mathematics and logic. The records related to each other by the laws of logic. That raises a previously held to be true (false ) set out to be false ( true), as well as other records must be corrected in their truth value according to the laws of logic.

For example: Consider the sentence set { " All men are mortal ", " Socrates is a man ", " Socrates is mortal "}. Suppose now, it turns out that Socrates is in fact not mortal but immortal. Then we need to ensure the consistency of the system, give up one of the other two sets.

Quine's point is found in the fact that it is not possible to say from the outset, which sets we would give up in such a conflict, whether we would so we decided in the above example to say that not all men are mortal, or that Socrates not human is. According to Quine can be held at any rate in principle, no matter look like new experiences. Contradict example, a new empirical experience a set on the periphery, so it can be stated at this time, by example, the new experience is explained to a hallucination. Conversely, no sentence is immune to revision. Thus it has been proposed that even abandon logical laws such as the law of excluded middle in order to simplify some quantum physics. A modification of the laws of logic would mean that not only the corresponding rates, but also the rules change according to which the truth values ​​are propagated in the network.

Indeed, it is by Quine so that it is the " natural tendency " are in the case of a new, contradictory experience to disturb the system as little as possible and therefore more likely to correct the sentences on the periphery than in the center, but this can be draw a sharp line. This consideration leads in Quine in the provocative thesis that there is no fundamental difference between the belief in physical objects and the belief in the gods of Homer. In both cases, if it were culturally related subsidence. The concept of physical objects has, however, " proved to be more efficient in the flow of experience a manageable structure to incorporate " ( " It has Proved more efficacious [ ... ] as a device for working a manageable structure into the flux of experience." ). Both concepts, however, are " underdetermined " by experience, ie the existence of physical objects can not be proved by reference to experience.

Quine thus confesses at the end of his essay into a continuous pragmatism: considerations that bring people to distort his scientific tradition to reflect its continuous sensory input, are where rational, pragmatic ( "the considerations Which guide [ you ] in warping his scientific heritage to fit his continuing sensory promptings are, where rational, pragmatic. ").