Logic is not concerned with concrete content, but with the laws of consistency. She asks, based on which rules out certain conditions specific ( “premises”) result or can not be drawn conclusions. To that extent, it addresses the basis of all argument- based science.
In earlier times the term “logic” was used in a wider sense than it is today. The example of the logic of the Stoa is typical. This also included the area that is now called epistemology, problems of language philosophy and rhetoric. The same is true of many logic books up to the early 20th century.
In modern philosophy, logic, the science of correct reasoning, only refers to formal logic. This overlaps with areas from mathematics and computer science. The logicists even think the whole mathematics is, apart from axiom finding, only logical derivation and reasoning. The extent to which logic extends to other areas (e.g. argumentation theory, speech act theory ) is, however, controversial.
The most important logicians in the history of philosophy include Aristotle, Chrysipp, Johannes Buridanus, Gottlob Frege, Charles Sanders Peirce, Bertrand Russell with Alfred N. Whitehead, Kurt Gödel and Alfred Tarski.
Epistemology asks about the possibility of acquiring and securing knowledge. The extent of knowledge, nature of knowledge, types of knowledge, sources of knowledge and structure of knowledge are examined, as well as the problem of the truth or falsity of theories. Epistemology puts the perception of reality to the test as well as the influence of language and thinking on the cognitive process. In addition, it tries to stake out the limits of knowledge and to define what can in principle be described as “scientific”. These since Immanuel Kant epistemological criticism has been the fundamental core of epistemology for many philosophers.
Important epistemologists were Plato, Aristotle, René Descartes, John Locke, David Hume, Immanuel Kant, Auguste Comte, Edmund Husserl and Ludwig Wittgenstein.
Philosophy of science
The philosophy of science is closely related to epistemology and analyzes or postulates the requirements, methods and goals of science. Above all, it defines the criteria for the terms “science” and “scientific” and tries to differentiate them from para- and pseudosciences. To this end, several basic methodological requirements that cannot be justified by the individual sciences themselves have emerged today. For example, the need for repeatability of experiments, the principle of economy (“Ockham’s razor”) and the principle of falsifiability as a prerequisite for meaningful scientific statements are components of these scientific models.
Furthermore, the philosophy of science deals with the relationship between scientific knowledge and the concepts of truth or reality. Also the possible division and order of human knowledge into areas and their hierarchization, as well as the investigation of the principles of scientific progress (cf. paradigm shift ) belong to her area of responsibility.
Important representatives of the philosophy of science are Aristotle, Francis Bacon, Rudolf Carnap, Karl Popper, Thomas Kuhn, Paul Feyerabend and Hilary Putnam.
Metaphysics and ontology
Metaphysics has almost always been at the core of philosophy. It tries to put the whole of reality as it appears to us in a meaningful context – often also in a universal system. She examines the foundations and general structures of the world. Furthermore, she asks the “last questions” about the meaning and purpose of all being.
Traditionally, metaphysics is divided into a general and a special branch. The general metaphysics is the ontology, which in the tradition of Aristotle poses the question of the basic structures of all beings and being. The subject area is unrestricted. In the history of philosophy, metaphysics is primarily shaped by three basic questions:
- Are there kinds of things that are fundamental to the existence of other kinds? (Aristotle’s “Categories”)
- Is there a first / last cause on whose existence the existence of everything else depends? (Aristotle)
- Why is there something at all and not nothing? (after Gottfried Wilhelm Leibniz, declared by Martin Heidegger as a basic question)
Special metaphysics is divided into three disciplines that ask the following questions:
- According to the existence of God and his possible properties (rational or natural theology );
- For the possibility of an immortal soul and free will, as well as for differences between spirit and matter (rational psychology );
- According to the cause, constitution and purpose of the universe (rational cosmology );
The natural sciences and their instruments cannot and do not want to deal with these questions for fundamental reasons, since the objects of metaphysics are in principle withdrawn from any (sensual) human experience. If the existence of areas of reality that cannot be empirically investigated is disputed or declared irrelevant, then the questions of metaphysics are superfluous. Traditional metaphysics has been criticized in two different ways. While positivism and advocates of analytical philosophy tended to push for the abolition of metaphysics through logical analysis of language in the first half of the 20th century, Martin Heidegger, for example, tried to create a new approach for an alternative metaphysics (fundamental ontology, existential philosophy) in overcoming the history of metaphysics and in a radical turn of the question to the analysis of human existence. In the meantime, traditional metaphysical, in particular ontological questions and problems are gaining broader attention in the philosophical discussion – also in much debated disciplines such as the philosophy of mind.
Important metaphysicians were Plato, Aristotle, Thomas Aquinas, René Descartes, Gottfried Wilhelm Leibniz and the representatives of German idealism and neo-scholasticism.
Philosophy of language
The philosophy of language examines the relationship between language, thought and reality. The analysis of language, e.g. by means of the precise decomposition of concepts, has always been practiced in philosophy. From the beginning, the paramount importance of language for communicative processes, finding truth, possibilities for knowledge and the description and perception of the world was a central theme of philosophy.
For example, the question was already discussed in antiquity whether a thing was given a certain designation “naturally” or only through an arbitrary definition by humans. The subsequent important topic of medieval philosophy – the problem of universals – can partly be understood as a problem in this area.
The modern philosophy of language in the 20th century, the so-called “linguistic turn”, triggered, dealt with the dependence of the apprehension of reality on the individual linguistic possibilities (cf. Sapir-Whorf hypothesis ), with the production of truth, knowledge and knowledge through communication ( cf. linguistic game), how one carries out actions with the help of linguistic utterances (John Langshaw Austin : how to do things with words, see pragmatics ), the distorting influence of language on reality (e.g. in feminist linguistics) and the question of what “Meaning” is.
The most important language philosophers include Gottlob Frege, Charles S. Peirce, George Edward Moore, Bertrand Russell, WvO Quine, Saul Aaron Kripke and Ludwig Wittgenstein. Ferdinand de Saussure (structuralism), Martin Heidegger (etymology and neologisms), Michel Foucault (discourse analysis) and Jacques Derrida (poststructuralism) also made important contributions.