One of the main purposes of science is to explain natural phenomena by increasing our understanding of the physical world and to make predictions about the future based on these explanations. In this context, scientific theories can be defined as large-scale explanations of phenomena. In the historical process, scientists have made various choices among the theories they encounter at the point of solving the problems related to their fields of study. This process, which can be called ‘theory choice’, is one (...) of the most debated issues in the field of philosophy of science in the twentieth century, because this discussion is a very comprehensive problem because it includes important issues such as the use of logical arguments and the determination of the scientific method. At the point of solving this problem, members of the Vienna Circle and Karl Popper think that an objective criterion can be determined by which scientists can apply for theory choice. While the Vienna Circle emphasizes that the best-confirmed theory should be chosen among competing theories, Popper states that competing theories or theories should be tested ruthlessly with appropriate methods, and that successful or corroborated theories should be selected as a result of these tests. Contrary to these views Kuhn states that there are some non-obligatory subjective elements that scientists should follow at the point of theory choice. Accordingly, in this study, the problem of how scientists make their choices among competing theories will be discussed by highlighting Kuhn’s arguments regarding the subjective nature of theory selection. (shrink)

This article initially presents Ernst Mach's anti-realist or instrumentalist stance that underpin his opposition to atomism and reveal his idea that science should be based totally on objectively observable facts. Then, the details of Mach's phenomenalist arguments which recognize only sensations as real are revealed. Phenomenalist thought is not compatible with the idea of realism, which evaluates unobservable entities such as atom, molecule and quark as mind-independent things. In this context, Mach considers the atom as a thought symbol or a (...) metaphysical fiction. This results in the idea that the existence of matter or entity is not independent of the perceiving minds, which is considered Mach’s subjective idealism. As a result of these arguments, the article argues that it would not be wrong to associate Mach's thoughts with solipsism, a radical form of subjective idealism. -/- Bu makalede ilk olarak Ernst Mach’ın atomun varlığına ilişkin itirazının temelini oluşturan ve bilimin sadece gözlemlenebilir olgulara dayandırılması gerektiği yönündeki düşüncelerini ortaya koyan anti-realist ya da enstrümantalist görüşlerine yer verilmektedir. Ardından Mach’ın enstrümantalist tavrının alt metninde bulunan ve yalnızca duyumları gerçek olarak kabul eden fenomenalist argümanlarının ayrıntıları serimlenecektir. Fenomenalist düşünce atom, molekül ve kuark gibi gözlemlenemeyen varlıkları zihinden bağımsız şeyler olarak değerlendiren realizm düşüncesi ile uyuşmamaktadır. Bu bağlamda yapılan incelemeler, Mach’ın atomu bir düşünce sembolü ya da metafiziksel bir kurgu olarak değerlendirmesine ve dış dünyadaki varlıkların var olmasını, onların bir zihin tarafından duyumsanması koşuluna bağlaması ile sonuçlanmaktadır. Makalede Mach’ın öznel idealizmi olarak ele alabileceğimiz bu argümanlarının radikal bir sonucu olarak onun düşüncelerini solipsizm ile ilişkilendirmenin yanlış olmayacağı sonucuna varılmaktadır. (shrink)

This paper aims to cast light on the reasons that explain the shift of opinion—from scepticism to realism—concerning the reality of atoms and molecules in the beginning of the twentieth century, in light of Jean Perrin’s theoretical and experimental work on the Brownian movement. The story told has some rather interesting repercussions for the rationality of accepting the reality of explanatory posits. Section 2 presents the key philosophical debate concerning the role and status of explanatory hypotheses c. 1900, focusing on (...) the work of Duhem, Stallo, Ostwald, Poincaré and Boltzmann. Section 3 examines in detail Perrin’s theoretical account of the molecular origins of Brownian motion, reconstructs the structure and explains the strength of Perrin’s argument for the reality of molecules. Section 4 draws three important lessons for the current debate over scientific realism. (shrink)