History of Philosophy

Schools of Contemporary Philosophy

Philosophy of Science

Another vibrant domain of philosophical discourse is the philosophy of science. The rapid development of science in the modern era has rendered it a central topic of philosophical reflection. Since Auguste Comte (1798-1857) initiated positivism, the conviction that empirical science is the most reliable means of knowledge, science has captivated numerous scholars. In the 20th century, the philosophy of science incorporated insights from the philosophy of language, given the obvious pivotal role of language in scientific endeavor. In 1922, Friedrich Albert Moritz Schlick (1882-1936) founded the Vienna Circle, a group of intellectuals dedicated to exploring the nature of science. The philosophical movement initiated by this circle is known as logical positivism. Notable members of the circle included Otto Neurath (1882-1945), Rudolf Carnap (1891-1970), Hans Reichenbach (1891-1953), and Alfred Ayer (1910-1989). Logical positivists held that the most reliable knowledge is obtained through methods employed by the natural sciences. Since natural sciences rely on experience, the logical positivists proclaimed experience as the sole source of knowledge. Knowledge derived from experience is expressed through linguistic statements, thus an understanding of the nature of scientific inquiry is impossible without appreciating the importance of language in this process. Logical positivists argued that people employ two types of judgments. The first type includes judgments with truth value, divided into two categories: protocol statements, which describe (or record) reality, and logical laws. The former are based on experience; the latter on logic. Protocol statements are meaningful only if they can be verified, that is, empirically tested. Judgments that cannot be verified or derived from logical laws are meaningless: they are neither true nor false but devoid of meaning. Such judgments, according to the positivists, create numerous problems for philosophy and science, and to avoid these problems, language should be cleansed of such statements. Thus, the logical positivists believed that science progresses as follows: experience generates knowledge; scientists accumulate this knowledge and inductively derive general laws; any statement that cannot be verified should be excluded from scientific discourse.

Not all agreed with the conclusions of the logical positivists. Karl Raimund Popper (1902-1994) became the founder of critical rationalism and, contrary to the positivists, argued that science operates with statements that cannot be verified. Scientific laws are universal statements, and general propositions neither follow from experience nor can be verified by experience. Verification applies only to singular statements. This implies that experience is not the source of knowledge. Popper posited that science functions as follows: a scientist initially forms an idea, which is then considered and, if it does not contradict common sense, tested against experience. If experience does not refute this theory, it is accepted by the scientific community. Experience produces only singular statements, while science operates with general ones. Hence, Popper argued that the source of scientific knowledge is not experience but the scientist. The role of experience, according to him, is not to prove the truth of scientific statements but to falsify them. Therefore, the truth of any scientific statement cannot be definitively proven. Scientists work with scientific theories, and every instance of applying a theory in practice risks its falsification. If a theory withstands rigorous testing over time, its credibility is enhanced. Since scientific statements cannot be fully proven, Popper rejected the logical positivists' distinction between meaningful and meaningless statements. Instead, he categorized statements as scientific or non-scientific. Scientific statements are those that can be criticized based on experience, while non-scientific statements are those that cannot be subjected to such criticism.

Popper's model of analyzing the nature of science was also applied to politics. He divided societies into open and closed types. Open societies are those where social relations and power institutions can be criticized. Closed societies are those where established orders cannot be criticized.

Imre Lakatos (1922-1974) founded the theory of refined falsificationism, according to which it is appropriate to distinguish two aspects in science: the core, which encompasses fundamental theories and methods, and the protective belt, which contains auxiliary hypotheses designed to shield the core from attacks. Experience continuously subjects scientific theory to criticism, attacking the protective belt. This compels it to strengthen its defenses against such attacks. Significant changes in the protective belt gradually alter the core of scientific theory. Thus, while Popper believed that experience, if it contradicts a theory, could falsify it, Lakatos argued that experience does not compel scientists to immediately abandon a theory. The theory evolves progressively, attempting to protect itself from experiential challenges.

Ludwik Fleck (1897-1961) developed the concept of thought styles and thought collectives. He posited that every individual, through education and upbringing, acquires a particular thought style. Along with others who share the same thought style, the individual forms a thought collective. The thought style shapes worldview, interests, modes of argumentation, and more. Each person simultaneously belongs to various thought collectives: one might adhere to the paradigm of contemporary physics, be a centrist in politics, a liberal in economics, a Muslim in religious views, and an admirer of classicism in art. Within each collective, two groups emerge: the esoteric circle, a small group that shapes the thought style and establishes its foundations, and the exoteric circle, the majority of collective members who adopt the thought style but do not contribute new features to it.

Thomas Samuel Kuhn (1922-1996) asserted that science undergoes two stages of development. In the first stage, which he called pre-science, there is no consensus among scientists on fundamental issues within their field of knowledge. The scientific community is divided into numerous competing schools and directions. Pre-science is inefficient as scientists expend effort and time determining which school to join and engaging in debates between schools, unable to align their results with those of their peers due to the small size of their circles. At a certain point, one of the pre-science schools gains dominance and displaces the others. This transition marks the shift from pre-science to normal science. At this stage, all scientists within a field recognize a single paradigm, a set of fundamental hypotheses, methods of scientific inquiry, objectives, etc. Normal science is marked by its efficiency, as scientists no longer waste effort on debates and can consolidate their efforts. The saved time and effort are directed towards addressing the core tasks of scientific inquiry, which involve solving puzzles, that is, seeking answers to questions aimed at reinforcing the paradigm.

However, sooner or later, reality presents scientific paradigms with questions that cannot be answered within the confines of the prevailing paradigm. Kuhn termed such questions anomalies. Initially, the scientific community attempts to ignore them, but among the younger scientists, there will inevitably be those who begin to focus on these anomalies and emphasize the paradigm's failure to provide adequate answers. The scientific community becomes divided between the older generation, who strive with all their might to salvage the paradigm, and the younger generation, who see the need for its replacement. Once scientists develop a new paradigm capable of explaining the anomalies, a scientific revolution occurs, signifying a shift in paradigms. After the revolution, scientific progress starts anew, as the new paradigm does not inherit anything from the old one. The entire history of science consists of continuous scientific revolutions and paradigm shifts.

Paul Karl Feyerabend (1924-1994) was the founder of scientific anarchism. He argued that science cannot grasp absolute truth, and thus any methods and frameworks established by science and its institutions represent a dictatorship that restricts the free flow of thought. Feyerabend called for a rejection of scientific truths and the establishment of a possibility for completely free inquiry.

Stephen Edelston Toulmin (1922-2009) developed an evolutionary theory of science. He posited that scientific knowledge can be categorized into two types of truths: those that are eternal and unchanging, and those that evolve over time. For instance, some things considered beautiful today were not regarded as such a thousand years ago, but at any time, people had concepts of beauty. Toulmin thus distinguished between field-dependent truths, which change according to context and continually evolve, and field-invariant truths, which remain constant regardless of circumstances.

A particularly significant issue in contemporary philosophical discourse concerns the status of mathematics. Mathematics is fundamentally different from other sciences: while natural sciences rely on empirical data, the truth of mathematical statements is independent of experience. For example, the Pythagorean theorem would be true even if there were no triangular objects in the world. The question of the nature of mathematical truths has become a central topic in the philosophy of mathematics. Historically, mathematical realism, founded by Pythagoras and Plato in Antiquity, has dominated the philosophy of mathematics. Realists assert that mathematical truths exist as a distinct reality that cannot be reduced to anything else. In the 20th century, with the rise of postmodernism in European civilization, which saw a tendency to reject all that is eternal and unchanging, criticism of mathematical realism emerged. Having rejected realism in mathematics, theorists in this field faced the challenge of explaining the nature of mathematical truths. If mathematics does not have its own existence, as those who rejected realism argued, then the only way to explain it is by reducing it to something else. This led to the development of numerous theories in the philosophy of mathematics: logicism (Gottlob Frege, Bertrand Russell) viewed mathematical truths as derived from logic; formalism (David Hilbert) considered mathematics as an intellectual game; and conventionalism (Henri Poincaré) regarded mathematics as the result of agreements among specialists.