The Knowledge Machine
Did an unreasonable idea create modern science?
Michael Strevens holds that scientific thought is strange and that its strangeness is the reason why it arrived so late in human history. It is strange because it dispenses with anything other than evidence, than empirical test. Because the validity of the explanations of the phenomena being studied is only made to depend on the evidence in their favor. Strevens calls this code of behavior "the iron rule of explanation".
Science, Strevens maintains, is boring, frustrating. At least 99% of the time. Readers of popular science only see the 1%: intriguing phenomena, provocative theories, dramatic refutations or experimental verifications. However, behind that 1% and as any scientist knows, there are long hours, days, months of tedious laboratory work. Thus, he believes that the greatest obstacle to successful science is the difficulty of persuading brilliant minds to abandon the intellectual pleasures of permanent debate and speculation, theorizing and arguing, and instead to adopt a life consisting entirely of the production of experimental data.
The scientific enterprise thus has a problem of motivation. The problem is not motivating students to become scientists; nor is it motivating scientists to go to the lab every day –they are paid to do so– or to observe, measure and experiment when they are there, since that is what they are supposed to do. The problem is to motivate the extraordinary intensity and long-term commitment with which the experimental contrast must be made in order to do the best science.
Science is driven by discussions among its practitioners, who have trained their minds and want to convince or at least refute their rivals. Opinions that precede established facts constitute the force of scientific enquiry.
A defining feature of science, in Strevens' view, is its essential subjectivity. It cannot be otherwise, and that is precisely what makes Popperian refutation so controversial. Scientific theories carry a whole cohort of assumptions or auxiliary premises, but when two alternative scientific theories are faced against each other, it is usually not possible to independently verify those premises. In such cases, scientists assign a higher probability of validity to one than the other. These are not arbitrary attributions –they are based on our experience– but they are subjective, as each of us will make attributions based on personal experience or aspirations. And because of this, the estimation of the weight, the importance of the evidence will vary from one scientist to another.
By virtue of the "iron rule of explanation" we scientists resolve our differences of opinion by means of empirical tests. The rule tells us how to debate, how to devise subsequent tests to resolve a disagreement. But that is not enough to reach agreement, however. A shared sense of what counts as an empirical test is also needed. The iron rule provides the necessary definition, an objective criterion for the empirical test to which all scientists adhere. Such a test requires an experiment or other observation or determination, one of whose possible outcomes can be explained by one hypothesis (and its accompanying premises), but not by the other. Despite its apparently modest ambitions, consensus on procedure is precisely what ensures the triumph of modern science.
As evidence accumulates, the plausibility rankings of competing theories begin to converge. Differences of opinion among scientists become smaller and smaller. A consensus emerges as to which are the leading contending theories and which are the losers, and finally, which is the best of all. There may not be total agreement, but there is less and less disagreement. This is called Baconian convergence.
Newton was instrumental in defining the methodological framework of modern science –the iron rule. He did so by asserting that in experimental philosophy there was no place for hypotheses, whether physical or metaphysical, or based on occult or mechanical qualities.
He thus escaped the endless circles of explanatory relativism and gave scientists an "ahistorical and timeless criterion" for explanatory power to serve as raw material for an iron rule that dictates, in return, a fixed criterion that determines what counts as legitimate empirical evidence. A scientific theory postulates some causal principles; what it explains is whatever can be logically derived from those principles. This is the standard for explanation, which means the same thing in all places and times.
The Newtonian iron-rule criterion for explanatory power applies to complete theoretical cohorts –the theories together with their auxiliary premises– rather than to theories alone, unaccompanied by their auxiliaries. It provides an objective test, devoid of ideology, for assessing whether a cohort explains a phenomenon: can the phenomenon be derived from the cohort's causal principles and facts?
In the postscript to the second edition of the Principia (1713), Newton wrote that "anything not deduced from phenomena must be called a hypothesis; and there is no place for hypotheses in experimental philosophy". It can be seen, therefore, that Newton's view of scientific enquiry was extremely austere. Nothing other than verifiable facts was admissible when it came to accepting a scientific theory as valid.
If science only admits, for the purpose of verification or refutation of theories or hypotheses, the empirical contrast, it means that it must disregard other considerations –theological, philosophical, aesthetic or any other. In a way, this attitude –according to the author– is irrational, as it implies a deliberate intellectual impoverishment.
The iron rule may impose irrationality on scientific argument, but it is a strategically brilliant irrationality, which manipulates its human subjects –the scientists– to engage vehemently with the empirical details that make modern science a formidable knowledge-creation machine.
This dissection that leads to leaving aside the recourse to empirical contrast and to the other all other considerations only had been possible thanks to a very particular historical circumstance. The price of peace after the Thirty Years' War in Europe was a permanent bisection of the moral domain into non-overlapping spheres of obligation, Holy Church and Sovereign Nation, each with its proprietary principles and its separate webs of duty and just merit.
To Aristotle and his Muslim and Christian followers in the Middle Ages, the proscription of philosophical and theological arguments by the iron rule would have seemed arbitrary and indefensible. To a seventeenth-century mentality, by contrast, the rule asked of its followers no more than what the political and religious settlement of the time had asked: that a dedicated intellectual space be reserved for its exercise, within which only a strictly restricted set of principles would be allowed to govern the course of reasoning. Partition –civil and spiritual– was the order of the day. Thus, the cognitive and logical partitioning of the iron rule might well have seemed clear, elegant, glamorous and irresistibly "modern". Once radicals like Bacon brought the central features of science governed by iron rule to the table, they were taken more seriously than they would have been at any other time in human history.
Even as Newton's work became an object of universal admiration, something more subtle was emerging: the recognition of a division between public argument in the official channels of scientific communication, properly policed by iron rule, and private thought, where philosophy, theology and beauty have free rein.
After Newton, the adoption of the iron rule was greatly helped by limiting the scope of its edicts against subjectivity and non-empirical argument to scientific journals and the like, leaving private reasoning unrestricted –a self-imposed limit to the power of the rule that is an essential part of modern science as we know it. Indeed, what set 17th century Europe apart from other eras was that the division between public and private was largely normalized and largely socially accepted.
Thanks to its nascent liberalism, then, the European seventeenth century distinguishes itself from elsewhere in history by explicitly discussing, regulating and sometimes celebrating the segregation of tightly controlled outside expression and unfettered personal opinion. This goes some way to explain how those who drew on Newton's science found it natural and easy to conform to the strictures of the iron rule in public scientific debate, even as their minds trafficked in ideas they dared not express aloud.
The 17th century was ready for the iron rule, and when it appeared, it made the most of it: it created modern science.
The above is a synthesis of the aspects of Michael Strevens' book that I have found central to his thesis and of most interest. As far as this commentator is concerned, I have no clear opinion about his line of argument. In general terms I find his approach to the origins of modern science convincing. Newton's importance is undoubted and the mark he left is indelible. Even today, some of my scientific colleagues argue that our task should be limited to describing how the phenomena we observe occur, limiting ourselves to unravelling the "hows" and explicitly refraining from inquiring into the “whys”. This is another way of expressing Newton's idea, quoted above, that "there is no place for hypotheses in experimental philosophy".
In my view, that is an extreme position. At the other extreme would be the full-throated defense of hermeneutics (interpretation) as the only or the main way to reach the truth.
In my opinion, however, it is very difficult in science to do without explanations based on whys. This is because whys –insofar as they are vehicles for expressing causal relations– are essential to provide explanations with the narrative nature that the human mind needs to appropriate the scientific fact, to make it its own, to humanize it, in short.
Strevens, not by chance, turns to quantum mechanics to exemplify that "scientific" way of thinking that offers "shallow" explanations, explanations that, in reality, are not such, but are limited to stating the sequence of facts and, if anything, the description of how those facts happen.
Quantum mechanics is, from this point of view, an "anti-narrative" scientific theory. That is why it is alien to human experience. And for that reason, only mathematical metaphors can describe it, even if its predictions are astonishingly accurate.
Strevens says that modern science exists because we scientists can do in private –to lucubrate, to philosophize, to appreciate the beauty of scientific models– what we are not allowed to do in our official expressions. So be it. But science, if it does not show young students and the general public a more "human" face, more in tune with the "narrative" mind of human beings, may end up having a legitimation problem.
Title: The Knowledge Machine – How an Unreasonable Idea Created Modern Science
Author: Michael Strevens
Published by Penguin Books, 2021.