Helgoland Rovelli, Erica (cat reading book .TXT) 📖

chief polemical target was eighteenth-century mechanism: the idea that all phenomena are products of matter that move through space. Mach argues that the progress of science shows that this notion of “matter” is an unjustified “metaphysical” assumption: a model that was useful for a time, but which we needed to move past, so that it does not become a metaphysical prejudice. Science must be freed from all metaphysical assumptions: knowledge should be based, that is, only upon what is “observable.”

Does this remind you of anything? This is exactly the premise of Heisenberg’s magical work conceived on the island of Helgoland—the work that opened the way to quantum theory and the story told in this book. Heisenberg’s article begins thus: “It is the aim of this work to lay the foundation for a theory of quantum mechanics based solely on relations between quantities that are in principle observable.” Almost a quotation from Mach.

The idea that knowledge must be founded on experience and observations is certainly not original: it is the classical tradition of empiricism that goes back to Locke and to Hume, if not all the way back to Aristotle. But the focus upon the relation between the subject and the object of knowledge, and doubts about the possibility of knowing the world “as it really is,” had led to the great German idealists and the philosophical centrality of the subject who holds the knowledge. Mach, a scientist, diverts this attention from the subject to experience itself—to what he calls “sensations.” He studies the concrete form in which scientific knowledge grows on the basis of experience. His best-known work examines the historical evolution of mechanics.86 It interprets it as the effort to summarize in the most economical way the known facts on movement as revealed by sensations.

Mach does not see knowledge as a question of deducing or intuiting a hypothetical reality beyond sensations, but as the search for an efficient organization of our way of thinking about these sensations. The world that interests us, for Mach, is constituted by sensations. Any firm assumption about what lies “behind” those sensations is suspect as being a form of “metaphysics.”

The notion of “sensation” is ambiguous in Mach. This is both his weakness and his strength: Mach takes the concept of sensation from physiology but makes it serve as a universal notion independent from the psychological sphere. He uses the term “elements” (in a sense similar to dhamma in Buddhist philosophy). “Elements” are not just the sensations that a human being or an animal experiences. They are any phenomena that manifest themselves in the universe. The “elements” are not independent: they are tied by relations, what Mach calls “functions,” and these are what science studies. Though imprecise, Mach’s philosophy is a real natural philosophy that replaces the mechanism of matter that moves in space with a general set of elements and functions.87

The appeal of this philosophical position is that it eliminates every firm hypothesis concerning a reality that exists behind appearances, but also every hypothesis on the reality of the subject who experiences. For Mach, there is no distinction between the physical and the mental world: “sensation” is equally physical and mental. It is real. Bertrand Russell describes the same idea thus: “the raw material out of which the world is built up is not of two sorts, one matter and the other mind; it is simply arranged in different patterns by its inter-relations: some arrangements may be called mental, while others may be called physical.”88 The idea of a material reality behind phenomena disappears; the idea of a spirit that “knows” disappears. Knowledge is possessed, for Mach, not by the abstract “subject” of idealism: it is instead the concrete human activity, in the concrete course of history, that learns to better and better organize the facts of the world with which it interacts.

This perspective, historical and concrete, resonates with the ideas of Marx and Engels, for whom knowledge is part of a concrete human history. Knowledge is divested of any ahistorical element, of every aspiration toward the absolute or pretense of certainty; it is located instead in the actual biological, historical and cultural evolution of mankind on our planet. It comes to be interpreted in terms of biology and economics, as a tool for simplifying our interaction with the world. It is not a definitive acquisition but an ongoing process. For Mach, knowledge is the science of nature, but its perspective is not far from the historicism of dialectical materialism. The consonance between Mach’s ideas and those of Engels and Marx is developed by Bogdanov and gains currency in prerevolutionary Russia.

Lenin’s response is scathing. In Materialism and Empirio-Criticism he launches an all-out attack upon Mach, his Russian disciples and, by implication, Bogdanov. He accuses them of that gravest of sins: the practice of “reactionary” philosophy. In 1909, Bogdanov is expelled from the editorial committee of The Proletarian, the underground newspaper of the Bolsheviks, and shortly after from the Central Committee of the party.

Lenin’s critique of Mach and Bogdanov’s reply interest us here.89 Not because Lenin is Lenin, but because his criticism is the natural reaction to the ideas that led to quantum theory. The same criticism occurs naturally to us. Precisely the issues debated by Lenin and Bogdanov have returned in contemporary philosophy. Their discussion provides a key for understanding the revolutionary significance of quanta.

Lenin accuses Bogdanov and Mach of being “idealists.” An idealist, for Lenin, negates the existence of a real world beyond the spirit and reduces reality to the content of the mind.

If only “sensations” are real, argues Lenin, then external reality is assumed not to exist: we live in a solipsistic world where there is only myself and my sensations. I take myself, the subject, as the only reality. This idealism, for Lenin, is the ideological manifestation of the enemy: it is pure bourgeois-ism. Against idealism, Lenin poses a materialism that sees the human being—human consciousness, human spirit—as an aspect of a concrete world that is objective, knowable,