Contemporary Science
No absolute criteria exist for the “periodization” of historical events, and such more or less conventional criteria vary according to the particular domain considered, so that the periodizations of political history, history of literature, history of philosophy, history of science, history of fine arts—for example—are usually not overlapping.
Owing to this, we propose to qualify as “contemporary” science that which begins in the last decades of the nineteenth century and continues up to now. Its defining characteristic is that of being the science of the unobservable, with a special reference to physics. Modern natural science had made abundant use of idealizations, that is, of concepts and statements that were an abstract representation of things and processes observable in ordinary experience, and were “visualizable”. Therefore, a certain confidence was spontaneous in admitting the “real existence” of such idealized entities when used in theories. For example, a corpuscular theory of light and a wave theory of light allowed scientists to conceive a light beam as consisting of a swarm of microscopic particles, analogous to grains of sand, travelling in the empty space or, respectively, in a wave propagating itself in an impalpable medium, analogous to the waves we see when a small stone falls in a pond of quiet water. This visualizability was the intrinsic force of such “mechanical models” which, in addition, constituted the intuitive basis for the elaboration of the rich mathematical apparatus of what was later called “classical mechanics”. It was precisely the failure of these models in accounting for the second principle of thermodynamics and of the properties of the electromagnetic field that gradually led to phenomenalist and anti-realist positions such as that of Mach: unobservable entities may be introduced in a scientific theory as useful tools for organizing ideas and permitting more or less accurate predictions, but do not correspond to physically existing objects.We can note that also in mathematics something similar was happening: the construction of the non-Euclidean geometries whose statements are often in contrast with the geometric intuitions, but are nevertheless on an equal footing with the Euclidean geometry as far as their internal non-contradiction is concerned, was opening the way to a purely formalistic and widely conventionalist conception of mathematics.
There is something puzzling in the situation we are considering. Contemporary natural science can be qualified in a broad sense as a science of the unobservables in multiple senses; because it has accomplished astonishing advancements in the investigation of the “microworld”, as well as in the description of the almost unthinkably enormous spatiotemporal dimensions of the universe, or in the penetration of the hidden structure of living matter and living beings. These advancements have been possible thanks to a strict synergy of theoretical thinking and technological development that has permitted us to ‘observe’ instrumentally a great number of features that the pure sensory observation cannot attain. One must be aware, however, that we can rely on such ‘observations’ only because we accept the theories on whose grounds the sophisticated instruments have been designed and their outputs are interpreted (and even ‘visualized’). Therefore, if we are not ready to accept that the elementary particles, or the DNA, or the extragalactic celestial bodies exist, we simply say that today’s natural science is unable to know nature as it really is, contrary to what was capable to do classical science. More than simply puzzling, this position is paradoxical since is advocated in general by positivists, that is, by people who attribute to science the privilege of being the best form (if not even the only genuine form) of knowledge.
One can wonder how such a strange attitude could arise and become widespread. The answer is historical. The already mentioned difficulties of ‘reducing’ to classical mechanics the explanation of fundamental thermodynamic and electromagnetic phenomena was only the announcement of a crisis that had found especially in Mach an explicit forerunner due to his radical empiricism, but literally exploded at the beginning of the twentieth century with the creation of quantum mechanics and relativity theory.
With these theories several laws and principles of classical mechanics were proved not to hold in the newly discovered domains, and even fundamental concepts seemed to have lost their original meaning. The whole of this well-known situation was (and still is) described by saying that classical physics had been proved to be false. And precisely because it had been found false despite its sophisticated mathematical formulation, the great number of empirical and experimental confirmations in different domains, and an incredible display of technological applications, it seemed wise the learn the lesson and say that no new scientific theory could advance the pretension of being finally the true one. No scientific theory is expected to be true and, therefore, the entities it introduces in its discourse are not expected to be real. In conclusion, the crisis of scientific realism was the historical consequence of having considered false classical mechanics and having therefore excluded truth from science. This is not an arbitrary reconstruction and is well reflected in the way in which Bas van Fraassen characterizes scientific realism in a celebrated work: realism is the position according to which “science aims to give us, in its theories, a literally true story of what the world is like; and acceptance of a scientific theory involves the belief that it is true”.[11]A consequence of this awareness is that, in order to vindicate a realist conception of science, one has to give back to science the traditional privilege of being a true discourse, obviously with all the precisions necessary for removing the obstacles that had led people to believe that even the best theories of classical mechanics were false.
This philosophical endeavor can profitably start by considering what has been proposed as an honorable replacement for truth in order to save the cognitive value of science, and then by a deepening of the very concept of truth.
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