Novel Predictions and the No Miracle Argument

Abstract

Predictivists use the no miracle argument to argue that ‘‘novel’’ predictions are decisive evidence for theories, while mere accommodation of ‘‘old’’ data cannot confirm to a significant degree. But deductivists claim that since confirmation is a logical theory-data relationship, predicted data cannot confirm more than merely deduced data, and cite historical cases in which known data confirmed theories quite strongly. On the other hand, the advantage of prediction over accommodation is needed by scientific realists to resist Laudan’s criticisms of the no miracle argument. So, if the deductivists are right, the most powerful argument for realism collapses. There seems to be an inescapable contradiction between these prima facie plausible arguments of predictivists and deductivists; but this puzzle can be solved by understanding what exactly counts as novelty, if novel predictions must support the no miracle argument, i.e., if they must be explainable only by the truth of theories. Taking my cues from the use-novelty tradition, I argue that (1) the predicted data must not be used essentially in building the theory or choosing the auxiliary assumptions. This is possible if the theory and its auxiliary assumptions are plausible independently of the predicted data, and I analyze the consequences of this requirement in terms of best explanation of diverse bodies of data. Moreover, the predicted data must be (2) a priori improbable, and (3) heterogeneous to the essentially used data. My proposed notion of novelty, therefore, is not historical, but functional. Hence, deductivists are right that confirmation is independent of time and of historical contingencies such as if the theorist knew a datum, used it, or intended to accommodate it. Predictivists, however, are right that not all consequences confirm equally, and confirmation is not purely a logical theory-data relation, as it crucially involves background epistemic conditions and the notion of best explanation. Conditions (1)–(3) make the difference between prediction and accommodation, and account for the confirming power of theoretical virtues such as non ad-hocness, non-fudging, non-overfitting, independence and consilience. I thus show that functional novelty (a) avoids the deductivist objections to predictivism, (b) is a gradual notion, in accordance with the common intuition that confirmation comes in degrees, and (c) supports the no miracle argument, so vindicating scientific realism

Resisting the historical objections to realism: Is Doppelt’s a viable solution?

“…Novel predictions can be explained only by showing that the theoretical claims essential to their derivation were true (Psillos 1999, p. 104 ff. ;Alai 2014aAlai , 2014c. From this point of view they are radically different from the predictions of known phenomena, which can be made even by false theories, if the theorists decide to account for those phenomena, and are patient and ingenious enough to accommodate them.…”

“…9 Including novel retrodictions, or novel explanations: i.e., the derivations of previously known phenomena which were not used in building the theory: seeAlai (2014a).…”

Optimism for Naturalized Social Metaphysics: A Reply to Hawley

“…Exactly what distinguishes a novel prediction from the mere accommodation of data is the subject of a long-standing debate (Alai 2014; Musgrave 1974; Worral 1982). Intuitively, it seems that if a theory is able to predict some event before it happens, that more strongly confirms the theory than explaining the same event after the fact.…”

The Underdetermination of Theories and Scientific Realism

“…Secondly we have (b) various "interpretations" of the standard theory, which differ on how to understand the wave function, the non-commutativity of operators, measurement, the completeness or not of the theory, determinsim or not, etc. They are Bohr and Heisenberg's 5 "Copenhagen" interpretation, De Broglie's "double solution", Wigner's theory of the collapse as produced by conscience, relational quantum mechanics, statistical quantum mechanics, informational interpretations and informational ontologies, modal interpretations, and the coherent histories interpretations. 6 These interpretations are in principle absolutely EE.…”

“…(2) In addition, Stanford's pessimism (like the pessimistic induction) can be resisted by Kitcher's (1993) and Psillos' (1999) deployment realist strategy: many of the best theories at each time, although later recognized as false, included some true claims, which are preserved in successor theories: it must be so, otherwise the novel predictions issued by those theories would be a miracle (Alai 2014b).…”