According to Carnap, the introduction of logical analysis (in the form of logical-empiricism) to clarify the meaning of terms in a sentence ultimately leads to a radical elimination of metaphysics as the statements of metaphysics become “meaningless”.
Carnap defines “meaningless” here in the strict sense of the word =
”… a sequence of words is meaningless if it does not, within a specified language, constitute a statement. It may happen that such a sequence of words looks like a statement at first glance; in that case we call it a pseudo-statement” p. 61
Two kinds of pseudo-statements =
- they contain a word which is wrongly believed to have meaning
- the constituent words are meaningful, but are put together in a counter-syntactical way so that they do not yield a meaningful statement.
- E.g. “Cesar is a prime number”. According to Carnap, the sentence follows the the rules of syntax (the third position is occupied by a predicate i.e. a noun/adjective), but it is meaningless because “prime number” is a predicate of numbers, and cannot be affirmed or denied by a person. Since the sentence looks like a sentence but does not express neither a true nor a false proposition, it is a pseudo-statement1
pseudo-concept = a word that seems to have meaning but doesn’t According to Carnap, all words in a traditional language originally have a meaning, but with time, the word may lose its old meaning without acquiring a new one, forming a pseudo-concept.
syntax = the mode of its occurrence in the simplest sentence form in which it is capable of occurring (this sentence form is the word’s elementary sentence)
- the elementary sentence form for the word “stone” = x is a stone
defining meaningful words
“In this way every word of the language is reduced to other words and finally to the words which occur in the so-called ‘observation sentences’ or ‘protocol sentences” p. 63
Carnap argues that a word or sentence is meaningful only if it can be connected, through a chain of definitions and rules, to observation (or protocol) statements. The reduction here does not mean that every theoretical term must be explicitly translated into observation terms, just that there are clear rules on how those statements using those terms are empirically tested.
According to Carnap, metaphysical terms fail this requirement because they cannot be reduced, even indirectly, to observation sentences. Since no possible experience could verify or falsify them, they lack cognitive meaning.
Carnap gives four possible ways of determining if a word a is meaningful =
- the empirical criteria for a are known = “temperature” thermometer reading
- logical formulation = we can connect sentences containing a to protocol statements
- semantic formulation = the truth conditions for the elementary sentence is fixed (it is always true/false)
- the method of verification for the elementary sentence is known
defining meaningful sentences
According to Carnap, there are three types of meaningful sentences =
- analytical statements / tautologies these statements say nothing of reality, e.g. logic and mathematics
- negations of statements = contradictions they are self-contradictory by virtue of their form
- statements that are true or false based on the protocol sentences = empirical statements
Since, the meaning of a sentence lies in the method of verification, that is only possible for an empirical proposition, anything beyond experience cannot have any meaning.
Carnap on analytical statements =
“there are statements which are true solely by virtue of their form (… “analytic judgments”). They say nothing about reality. The formulae of logic and mathematics are of this kind. They are not themselves factual statements, but serve for the transformation of such statements.”
Role of metaphysics
Carnap argues that metaphysical statements are pseudo-statements because they do not describe the state of affairs or make actual claims about the world. They lack empirical criteria, truth conditions, and methods of verification, and so cannot be true or false.
Meaningful metaphysical claims also cannot exist because of the very aim of metaphysics = to discover and formulate a kind of knowledge which is not accessible to empirical science
For Carnap is not dismissing metaphysics as useless, but instead sees metaphysical claims express a way of seeing the world and to communicate a person’s general attitude or worldview towards life, rather than to convey knowledge.2
Role of philosophy
“But what then is leftover for philosophy, if all statements whatever that assert something are of an empirical nature and belong to factual science? What remains is not statements, nor a theory, nor a system, but only a method: the method of logical analysis. … It is the indicated task of logical analysis, inquiry into logical foundations, that is meant by ‘scientific philosophy’ in contrast to metaphysics.” p.77
Carnap believes that all factual knowledge belongs to empirical sciences, and that philosophy cannot compete with science by making factual claims about reality. Since it cannot be a theory, or system of truths about reality as these roles belong to empirical science or collapse into metaphysics (pseudo-statements), philosophy becomes a method of logical analysis.
The task of philosophy (i.e. philosophy of science in particular) is to clarify concepts, analyze the logical structure of scientific language and investigate its logical foundations.
Carnap on “scientific philosophy”
For Carnap, Scientific philosophy is devoted to the analysis of the logic of science as opposed to the history of science (Kuhn), psychology of science (the cognitive aspect of science = personal thoughts, bias, etc.), etc.
Carnap’s view of scientific philosophy is focused on the context of justification and is a descriptive account of science (but may end up being normative).3
Carnap’s Aim of science according to logical empiricism supports an anti-realist account of science that the goal of science is to articulate patterns in observations, and simply uses theoretical terms as tools. This is based by Carnap’s view that metaphysics (determining what is real) is meaningless and so that cannot be science’s goal. Carnap’s view of science is prioritizing observations and predictions.