Inductivism

Inductivism is the traditional model of scientific method attributed to Francis Bacon, who in 1620 vowed to subvert allegedly traditional thinking. In the Baconian model, one observes nature, proposes a modest law to generalize an observed pattern, confirms it by many observations, ventures a modestly broader law, and confirms that, too, by many more observations, while discarding disconfirmed laws. The laws grow ever broader but never much exceed careful, extensive observation. Thus freed from preconceptions, scientists gradually uncover nature's causal and material structure.At 1740, David Hume found multiple obstacles to use of experience to infer causality. Hume noted the illogicality of enumerative induction—unrestricted generalization for particular instances to all instances, and stating a universal law—since humans observe sequence of sensory events, not cause and effect. Humans thus perceive neither logical nor natural necessity or impossibility among events. Later philosophers would select, highlight, and nickname Humean principles—Hume's fork, problem of induction, and Hume's law—although Hume accepted the empirical sciences as inevitably inductive, after all.Alarmed by Hume's seemingly radical empiricism, Immanuel Kant identified its apparent opposite, rationalism, as favored by Descartes and by Spinoza. Seeking middle ground, Kant identified that the necessity bridging the world in itself to human experience is the mind, whose innate constants thus determine space, time, and substance and determine the correct scientific theory. Though protecting both metaphysics and Newtonian physics, Kant discarded scientific realism by restricting science to tracing appearances (phenomena), not unveiling reality (noumena). Kant's transcendental idealism launched German idealism—increasingly speculative metaphysics—while philosophers continued awkward confidence in empirical sciences as inductive.Refining Baconian inductivism, John Stuart Mill posed his own five methods of discerning causality to describe the reasoning whereby scientists exceed mere inductivism. In the 1830s, opposing metaphysics, Auguste Comte explicated positivism, which, unlike Baconian model, emphasized predictions, confirming them, and laying scientific laws irrefutable by theology or metaphysics. Finding experience to show uniformity of nature and thereby justify enumerative induction, Mill accepted positivism: the first modern philosophy of science, which, simultaneously, was a political philosophy whereby only scientific knowledge was reliable knowledge.Nearing 1840, William Whewell thought that the inductive sciences, so called, were not so simple, after all, and asked recognition of ""superinduction"", an explanatory scope or principle invented by the mind to unite facts, but not present in the facts. Mill would have none of hypotheticodeductivism, posed by Whewell as science's method, which Whewell believed to sometimes, via other considerations upon the evidence, render scientific theories of known metaphysical truth. By 1880, C S Peirce had clarified the basis of deductive inference and, although recognizing induction, proposed a third type of inference that Peirce called ""abduction"", now otherwise termed inference to the best explanation (IBE).Since the 1920s, although opposing all metaphysical inference via scientific theories, the logical positivists sought to understand scientific theories as provably false or true as to strictly observations. Though accepting hypotheticodeductivism to originate theories, they launched verificationism whereby Rudolf Carnap tried but never succeeded to formalize an inductive logic whereby a universal law's truth with respect to observational evidence could be quantified as ""degree of confirmation"". Asserting a variant of hypotheticodeductivism termed falsificationism, Karl Popper from the 1930s onward was the first especially vocal critic of inductivism and verficationism as utterly flawed models of science. In 1963, Popper declared that enumerative induction is a myth. Two years later, Gilbert Harman claimed that enumerative induction is a masked effect of IBE.Thomas Kuhn's 1962 book—explaining that periods of normal science as but a paradigm of science are each overturned by revolutionary science whose paradigm becomes the normal science anew—dissolved logical positivism's grip in the Anglosphere, and inductivism fell. Besides Popper and Kuhn, other postpostivist philosophers of science—including Paul Feyerabend, Imre Lakatos, and Larry Laudan—have all but unanimously rejected inductivism. Among them, those who have asserted scientific realism—that scientific theory can and does offer approximately true understanding of nature's unobservable aspects—have tended to claim that scientists develop approximately true theories about nature through IBE. And yet IBE, which, so far, cannot be trained, lacks particular rules of inference. By the 21st century's turn, inductivism's heir was Bayesianism.