The Logic of Scientific Discovery (Karl Popper)
By Benjamin Mora
Sir Karl Popper stands as one of the greatest philosophers of science to have ever lived. Popper’s seminal text The Logic of Scientific Discovery is among the most influential works of 20th century philosophy. Originally published in German as Logik der Forschung (“The Logic of Research”) in 1935, with the first English edition appearing in 1959, The Logic of Scientific Discovery is a coherent, intellectually exhilarating masterpiece.
With Popper’s lucid thought composition, one could easily comprehend the ideas expounded by the author. However, the text is so rich with a vast array of complex philosophy, logic, and probability theory—compounded by the pervasive usage of mathematical equations, Greek symbols, and quantum mechanics—it is a wonder that any person outside this particular field of philosophy could fully grasp Popper’s writing.
Popper assumes the reader has a thorough grasp on a broad range of concepts common in philosophy, science, and physics. In a footnote, Popper actually advises at first reading to skip large portions of the text dealing with probability theory, Bernoulli’s Theorem, statistical interpretations of Heisenberg’s uncertainty relations, indeterminist metaphysics, and so on. The original text only comprises half of the book, with the rest being appendices, 19 in total, delving into the mathematics of even more complicated concepts, including the general calculus of frequency in infinite classes, derivations of binomial formulae, and construction of models of random sequences. It seems safe to assume The Logic of Scientific Discovery is not easily accessible to educated readers, never mind to lay readers. Nonetheless, with the mathematics and equations aside, Popper’s chef-d’oeuvre should be widely read and discussed by the philosophers, and perhaps more importantly, the scientists of today. An understanding of Popper’s theories is indispensible for an appreciation of what differentiates science from other branches of knowledge, and what propels the advance of scientific discovery.
A scientist constructs hypotheses, or systems of statements, and tests them step by step against experience by observation and experiment. Popper in his book ventures to give a logical analysis of this scientific procedure. What are the ‘methods of the empirical sciences’, and what do we call ‘empirical science’? It is widely believed that empirical science is established using inductive methods/logic—a position actually opposed by Popper. An inductive inference is one that passes from particular statements to universal statements. However, it does not seem we are logically justified in inferring universal statements from singular ones—a thus far insoluble dilemma known as the ‘problem of induction’. Popper opposes all attempts to operate with the ideas of inductive logic in science and instead advances a theory that is described as the ‘deductive method of testing’.
By rejecting the ‘method of induction’, it would seem that Popper’s theory is open to the charge of depriving empirical science of its most important characteristic, viz. inductive logic, which functions as a ‘criterion of demarcation’, separating science from metaphysical speculation. Inductive logic is rejected by Popper as a suitable criterion of demarcation and replaced by—what would come to popularly characterize his theory—‘falsifiability’. Popper states, “I shall certainly admit a system as empirical or scientific only if it is capable of being tested [and refuted] by experience.”
Popper wraps up with a series of concise and elegant conclusions. Science does not contain certainties, Popper states, nor does it steadily advance towards some state of finality. “Bold ideas, unjustified anticipations, and speculative thought, are our only means of interpreting nature…. Those among us who are unwilling to expose their ideas to the hazard of refutation do not take part in the scientific game.” “[Science advances] towards an infinite yet attainable aim: that of ever discovering new, deeper, and more general problems, and of subjecting our ever tentative answers to ever renewed and ever more rigorous tests.”