4.19.2022
Last Week
The Structure of Scientific Revolutions
By Thomas S. Kuhn
Nowadays, the term "paradigm shift" is the sort of watered-down jargon stamped by businesses on incremental improvements. But when it first came into use, a paradigm shift meant something real. In The Structure of Scientific Revolutions, Kuhn coined the term to describe what happens when an entire field of study is made different.
Scientific progress, Kuhn believes, is idealized to the point of historical revisionism. From reading textbooks and attending classes, the takeaway is that science is a gradual process, with facts and deductions carefully added to the ever-growing pile of human knowledge. Old theories are readily replaced by new ones and quickly relegated to the confines of history, with each step bringing us a bit closer to the "truth." Kuhn takes issue with this view—science isn't just about solving puzzles, but functions as a fundamental means of perception. And because the world is so complicated, we need entire assemblies of theories, methods, and modes of reasoning, which form paradigms of thought. Scientific revolutions are paradigm shifts: they completely change how we see the world, but they don't come about with ease.
Less Wrong
Academics often debate what constitutes a "real science," and opinions vary based on purity, rigor, and social respectability. Kuhn, on the other hand, has a different view: real sciences are fields where everyone can agree on the same underlying paradigms. For instance, every modern biologist accepts the germ theory of disease, natural selection, and the DNA theory of inheritance. Physicists operated under Newtonian principles before Einsteinian ones, but in each era, everyone could agree on the same overall ideas. The problem is that switching paradigms is harder than it might seem at first.
The most basic requirement for a theory is falsifiability. If a framework is impossible to disprove, adherence becomes a matter of faith rather than reason. Falsifiability allows us to discard incorrect models in our search for truth. But when it comes down to swapping theories for another, science rarely turns on the results of a single experiment. Because entire careers depend on preexisting paradigms, there are enormous incentives to integrate anomalous results into the current framework. This flexibility isn't necessarily counterproductive—a good paradigm should be expressive enough to permit further research and elaboration. If we upended our entire model of the universe the second we saw a weird result, then nothing would ever get done.
That same assurance is what makes normal or puzzle-solving science possible. And it is only through normal science that the professional community of scientists succeeds, first, in exploiting the potential scope and precision of the older paradigm and, then, in isolating the difficulty through the study of which a new paradigm may emerge.
Historically, there are many cases where the old modes of thought stuck around for too long. The classic example concerns the geocentric view of the universe, which was unable to account for the retrograde motion of the planets in a universe that placed Earth at its center. Ptolemy's remedy was to keep adding "epicycles" that the other planets would rotate around, performing a sort of manual Fourier transform. As more accurate measurements contradicted the model, some even resolved to keep adding epicycles upon epicycles. Though the model could continue to fit the motions of the stars, its lack of elegance resulted in its demise.
In Kuhn's view, there are really two types of science: those that operate within a given paradigm and those that threaten to overturn it entirely. The majority of modern science—and virtually all funded research—works towards three goals: applying the paradigm to determine facts, verifying the predictions of the paradigm theory, and articulating the theory further. These aims fall under "normal science," which isn't concerned with finding different frameworks, but rather with "solving puzzles." In normal science, the paradigm is present in all findings; its assumptions are what allow it to take place at all.
In so far as he is engaged in normal science, the research worker is a solver of puzzles, not a tester of paradigms. Though he may, during the search for a particular puzzle’s solution, try out a number of alternative approaches, rejecting those that fail to yield the desired result, he is not testing the paradigm when he does so. Instead he is like the chess player who, with a problem stated and the board physically or mentally before him, tries out various alternative moves in the search for a solution. These trial attempts, whether by the chess player or by the scientist, are trials only of themselves, not of the rules of the game. They are possible only so long as the paradigm itself is taken for granted. Therefore, paradigm-testing occurs only after persistent failure to solve a noteworthy puzzle has given rise to crisis. And even then it occurs only after the sense of crisis has evoked an alternate candidate for paradigm. In the sciences the testing situation never consists, as puzzle-solving does, simply in the comparison of a single paradigm with nature.
Consensus Protocols
Even though switching paradigms is hard, it nevertheless happens—otherwise, we'd still be stuck believing that objects moved out of their own "essence," that diseases spread through "miasma," and that the Earth is at the center of the universe. Kuhn saw each science as moving through a cycle of change—eventually, every model accumulates enough anomalies to provoke a crisis. These crises provide opportunities for a model to grow or for the entire paradigm to change.
Once a crisis occurs, there are three ways it can be resolved. In the first case, normal science is flexible enough to incorporate it into the existing paradigm, thus expanding the existing theory. In the second case, the problem is intractable with current methods and left as an open question for further research. In the third case, however, the crisis is resolved with the birth of a new paradigm. But this isn't easy, because the early days of choosing between two competing theories are hard when there isn't much evidence to distinguish between them. In the absence of objectivity, concerns such as elegance, faith, and even national allegiances come into play.
Like the choice between competing political institutions, that between competing paradigms proves to be a choice between incompatible modes of community life. Because it has that character, the choice is not and cannot be determined merely by the evaluative procedures characteristic of normal science, for these depend in part upon a particular paradigm, and that paradigm is at issue. When paradigms enter, as they must, into a debate about paradigm choice, their role is necessarily circular. Each group uses its own paradigm to argue in that paradigm’s defense.
The underlying assumptions being made are simply too "incommensurable" and the world remains too complicated to be described by human thought. Paradigms are equally false, so we just have to rely on which is better at puzzle-solving or matches with what we see the most.
In the end, Kuhn's definition of paradigms is a bit vague, and it's not easy to go about identifying what truly qualifies as such. It's unclear if paradigms can be nested within each other, how they can overlap, or if they can be applied together. Perhaps the lack of a solid definition explains the term's overuse nowadays. But overall, in spite of some dry prose, the author does a decent job explaining how difficult it is to reach agreement even on the most objective of studies. Though Kuhn sometimes gives the impression that science is fundamentally subjective, his real focus seems to be that truth and explainability are not the only motivators of scientific progress. Like with all groups, scientists find themselves operating within languages, myths, and culture—rather than searching for the truth, we'd just like to be less wrong.
This Week
Masters of Doom
By David Kushner
Doom transformed the video games industry with its advanced graphics, multiplayer settings, and method of distribution. id Software, its developer, was responsible for other developments through games such as Wolfenstein and Quake. In Masters of Doom, Kushner tells the story of the technology and drama behind the firm and its founders.
