Kinds of Scientific Controversies

As the space allowed does not encourage indulging in too fine an analysis, let me distinguish three major kinds of scientific controversies. Reversing the order above, these can be described as follows.

First, there are controversies in which the parties implicated share both the constitutive and the interpretative background “assumptions” involved in the inquiry but not the participation and/or the preference “assumptions.” In other words, this kind of controversy involves only disagreements stemming from participating at different traditions, from following differing “styles of reasoning,” and from entertaining different subjective preferences as to what is worth pursuing, either at the substantive or at the methodological level. No incommensurability of any sort is involved here, and disagreement does not hamper communication. Each party understands almost perfectly what the other is doing and why it is being done; the “assumptions” they entertain lead them only to consider their own line of investigation as more promising. The almost forgotten controversy between the physicists supporting, with Chew, “particle” democracy” and those advocating “particle hierarchy,” or the still ongoing controversy between the proponents of a steady-state cosmological model and those championing the idea of an expanding universe (Pera 1987) belong to this category. Moreover, priority disputes and fights over the distribution of credit belong here, too. For obvious reasons, we can call controversies of this first kind surface controversies. To help come to grips with the deeper aspects of the cognitive dimension of science, surface controversies are not as probative, or as consequential, as those belonging to the following two categories, for, concerning precisely the cognitive level, controversies of this kind are quasi-immediately resolved after the new scientific result has been established. However, for understanding the social dimensions of the scientific endeavor, their significance is decisive: resolution at the cognitive level does not necessarily entail immediate resolution at the social level.

Differences in participation and preference “assumptions” cannot be telling, in the sense of giving rise to scientific controversies in their own right, unless the “assumptions” lying “deeper” in the background are shared. Accordingly, they will not concern us further in developing this classification.

The second kind of scientific controversy comprises those in which the parties implicated share the constitutive “assumptions” involved in the inquiry but not all the relevant interpretative “assumptions.” Some, the more benign, forms of incommensurability may be encountered here, as well as some communication problems. As I implied above, the Newton-Leibniz dispute, analyzed by Freudenthal (1986), as well as the debates over the adequate explanation of the baffling (in terms of the then reigning interpretation of the conceptual system of quantum mechanics) low-temperature phenomena, analyzed by Gavroglu and Goudaroulis (1989), are cases in point. Another example is the Bohr-Einstein exchanges over the interpretation of the quantum mechanical formalism.

That all parties participating at controversies of this second kind share the constitutive “assumptions” of the conceptual system involved constrains the deployment of such controversies decisively. Incommensurability phenomena and communication issues become really serious only to the extent that this conceptual system in itself is not yet developed far enough, which is to say that the constraints it imposes on the controversy are not yet sufficiently clear to the disputants. Independent of sociological and subjective considerations, which undoubtedly played their own role, this can explain the cognitive dimension of the readily apparent differences in exacerbation between the Newton-Leibniz conflict, on the one hand, and the more recent disputes, on the other: in the first case, the relevant conceptual system was less developed, and hence less constraining, than it was in the others.

The resolution of a scientific controversy belonging to this second kind, as it is effected through the disclosure of the interpretative “assumption(s)” implicated, either leaves intact the conceptual system involved (quantum mechanics showed that it had the capacity, as it stood, to account for low-temperature phenomena) or develops that system in a way that renders it capable to accommodate post hoc both parties of the controversy, with relatively minor adjustments of their initial positions. The Newton- Leibniz case and, for that matter, the controversy over the wave or the matrix formulations of quantum mechanics are good examples here. As said above, we are entitled to say that the controversy was indeed about unshared interpretative “assumptions” only after it has been resolved and the interpretation of the relevant conceptual system has been correspondingly clarified.

Finally, the third kind of scientific controversy comprises what we can call deep controversies. In scientific controversies of this kind, the parties implicated do not share some of the constitutive background “assumptions” involved in the inquiry. Without, again, paying too much attention to details, we can distinguish here two major subcategories.

First, there are the controversies implicating some of the background “assumptions” assuring the coherence and determining the identity of a conceptual system that is already well constituted within an already existing science. This is to say that the cognitive perspective on the world defining that science—together with all the substantive and methodological ingredients that go with it (Baltas 1997)—is not at issue. Important incommensurability questions and grave communication problems arise in such cases, but the fact that all parties in the dispute work within the same perspective not only constrains in important ways the deployment of the controversy, but also restricts substantially the areas where incommensurabilities appear and communication breaks down. The Lorentz-Einstein dispute or that between the proponents of the new quantum physics and those of classical mechanics are cases in point.

The second subcategory of deep controversies comprises those occurring when the very perspective defining a science is in the process of being carved out. The background “assumptions” at issue in such cases are not those constitutive of the new conceptual system that is in the process of being established. Rather, they are those determining the identity and assuring the coherence of the particular old theories that the new conceptual system constitutively challenges. Since the controversy is not deployed within the disciplinary confines of an established science, it is, as a rule, less focused than it is in the cases we encountered above, and in that sense it tends to spill all over the place. Almost any part of common wisdom, with the deeply entrenched background “assumptions” it harbors, may be called to the rescue against the threat, or the scandal, represented by the new, highly counterintuitive concepts. The dispute of Galileo with the Aristotelians exemplifies best this subcategory (Damerow et al. 1992), while the controversy opposing Volta to Galvani (Pera 1991) or that between Lavoisier and Priestley, which Pierluigi Barrota analyzes in his volume, can with qualifications be classified here, too.

Obviously, deep controversies are the most significant from the cognitive point of view. They are revolutionary processes whose stake is the establishment of a radically novel conceptual system. To repeat, this either inaugurates a new science, and hence opens a wholly new perspective on the world, or it challenges some highly confirmed theory within the confines of an already existing science. In both cases, the new view appears almost incomprehensible to those still holding to the old theories, while the reverse is not true. Those supporting the novel conceptual system are objectively in the position to know which are the weaker links in their adversaries’ strategy and thence to fight them better. The final resolution of a deep controversy is tantamount to the total victory of the new conceptual system. This is a victory showing no mercy: from the vantage point of the victors, and if sufficient time has passed, the defeated views appear no better than plainly irrational. Hard work is required in order to make the Aristotelian viewpoint sound less than ridiculous even to our undergraduate physics students, for example.

This last point implies that, on the present analysis, the existence, the deployment, and the outcome of scientific controversies of any kind do not involve in principle, and need not question the rationality of any of the participants. Once we accept that any inquiry and any debate cannot but rest on a background of “assumptions,” all the parties implicated, prospective winners and losers alike, can be as rational (or as irrational) as our pet theories of rationality might suggest without this impinging on any aspect of a scientific controversy. In the present volume, Philip Kitcher and Marcello Pera defend this view and elaborate on it from different angles, while Barrota makes the corresponding case very well on behalf of Priestley.

And this allows me to conclude. An attempt at classification as the present one, that is, an exercise in pure description with no normative import on issues of rationality and the like, would be senseless unless it aspires to be adequate to the subject matter it sets out to organize. It follows that the attempt hangs literally in the air unless concrete controversies, as many and as varied as possible, are studied in the detail required.