Tensions in natural philosophy

This essay was inspired by reading a lecture of T. S. Kuhn[1] entitled The Essential Tension, given in 1959. Kuhn's tension is that which exists between the problem-solving mode of "normal science" and the paradigm shift, which characterizes more revolutionary moments in science. His argument is that the problem-solving mode is the fertile soil which nurtures the paradigm shift. Hence the conservatism which is associated with the problem-solving mode is seen by Kuhn as a necessary defence against pseudoscience; tradition has a double character, since it protects the scientific process at the same time as resisting its revolutionary transformation. The parallel with the political process is rather obvious!

I want now to draw attention to a different parallel, namely that this social tension, as described by Kuhn, mirrors the condition of most, if not all, physical and biological systems. We often use the label "mechanical" as a synonym for "physical", but this is a dangerous, indeed erroneous, identification, which, throughout most of the 20th century, has led to a sterile debate about the relative virtues of Classical Mechanics and Quantum Mechanics. The fact is that no physical system is adequately described by a mechanical model, be it "classical" or "quantum"; that is why I have claimed[2] that Quantum mechanics is not science. I would claim that an adequate description, and hence an adequate theoretical modelling, requires always the recognition that every dynamical system exists within an environment, and this means that, in addition to the dynamical variables, normally finite in number, internal to the system, there are an infinite number of stochastic environmental variables.

Hence the "tension" between the dynamical and the environmental aspects of the physical system is mirrored by a "tension" in our description of the system, that is between determinism (or necessity) and stochasticity (or chance). This in turn is, I believe, the source of Kuhn's social tension in the scientific community. The problem-solving tradition of the "normal-scientific" community sees every challenge to its authority as dangerous, and the iconoclastic minority sees every such challenge as a possible opportunity to change the paradigm basis, or the ideology behind the science; both communities are, of course correct!

Indeed, it would be all too easy to caricature the normal-scientific community as one which recognizes only the internal (dynamical) variables, both of the physical systems they study and of the closed community they themselves inhabit; they would, according to this caricature, be equally blind to the stochastic environmental variables of the physical system, and to their own wider scientific duties.

The above is a caricature because, as Kuhn emphasizes, no significant paradigm shift ever occurs, except as a product of the problem-solving process. To borrow, for a moment, from the political language, we can easily discern, within the authority structure erected to protect normal from pseudo science, both conservative and liberal elements. While the conservatives place their emphasis on protecting science, the liberals are prepared to accept "orderly" changes of paradigm. In practice the latter attitude implies a readiness to consider even "revolutionary" proposals, provided they can be shown to originate in problem-solving activity. Hence, as in politics, there is ample space within which the budding revolutionary can operate, provided he understands the rules of the reformist authorities.

But I really mean understand! In science, as in politics, there is the revolutionary who thinks the reformist constitution is a charade, and who therefore does not have the patience to learn the rules of the game, still less the ethics which lie behind them. He will probably be the first to cry "censorship" and "repression" when he fails to find a ready public to hear his ideas.

So far the argument is not problematic, but now there is a difficulty. I have just given a justification for the relatively narrow-minded attitude which characterizes most of normal science. But it will be impossible to maintain such a generous attitude towards our formally-minded colleagues who persist in blindly following QM, and consequently who refuse to recognize the role of the field environment of all their mechanical systems. I suppose the solution to this problem lies in recognizing that the liberals, who are the only true scientists, know something of the direction of impending change, even when they are wielding their authority in a conservative manner. And, following the same line of argument, the QM authorities include a liberal component who have some instinctive understanding of the environmental factors. Otherwise they would not be able to exercise their liberalism, and we would not be able to publish anything.


  1. T. S. Kuhn, The Essential Tension: Selected Studies in Scientific Tradition and Change (University of Chicago, 1977), pages 225-239.
  2. T. W. Marshall, My home page