Tuesday, September 29, 2026

What are the assumptions of science?

 Science makes assumptions about the nature of the world and the nature of humanity. We are so used to these ideas that we may overlook that they are assumptions. Before the emergence of modern science, people did not necessarily believe these things were true. 

Existence of regularity and order

There are patterns and regularity in nature, even though at first glance this may not appear to be so. Nature is not completely random, chaotic, or unpredictable. Not every object or event is different from every other object or event. Some things are similar. Finding and describing this regularity is a challenge that requires persistent effort. Scientists assume the patterns are there and eventually they will discover them.

Existence of laws of nature

The order and regularity can be encoded in laws that describe diverse systems and situations. Often, the laws can be succinctly stated and may be written in a simple mathematical form.

Uniformity (universality)

 Many laws are believed to apply everywhere and for all time. For example, the laws of physics apply on earth and in outer space. In contrast, Aristotle claimed there were different principles involved in the motion of objects on earth and in the “heavens.” Things may change, but there are also laws describing how they change. Even though some laws have a limited range of applicability, that range can often be explicitly defined.

Intelligibility and rationality

Although humans have finite and fallible minds, they have the ability to discover and understand the laws of nature.

Objectivity

All observations and their analysis, interpretation, and communication involve human subjects. Yet, it is assumed that with due diligence, the results can be independent of human subjectivity.

Induction

Deduction is the rational process of making specific assumptions and then using the rules of logic to draw a conclusion. In contrast, induction is the process of moving from particular examples to making universal statements. For example, every day of my life, I have noted that the sun has risen. Everyone I ask agrees that this is true in their lives as well. Historical records confirm this to be true. And there are solid scientific reasons that verify this reality. From these observations, I induce the general proposition that for the rest of my life, and probably for much longer, the sun will continue to rise each day. Science is built on induction. Scientists make specific observations about the natural world, and from these observations they hypothesise a general proposition to hold for a wide range of circumstances beyond the initial observation.

Induction is not logically justified. Nevertheless, the success of science testifies to the value of inductive reasoning. But induction can fail when data is limited or difficult to obtain, mistakes are made in gathering or interpreting the data, or prejudice blinds someone when deciding what data to accept or reject. A famous example of the failure of induction was the existence of black swans.  In seventeenth-century Europe, this was considered an impossibility as all observed swans were white. However, in 1697 a Dutch expedition to Western Australia discovered black swans. The philosopher John Stuart Mill (1806-1873) wrote: “No amount of observations of white swans can allow the inference that all swans are white, but the observation of a single black swan is sufficient to refute that conclusion.”

On the one hand, the success of science suggests that making these assumptions is reasonable. On the other hand, why do we assume they will continue to be true, even when we have experiences, individually and collectively, where we fail to find patterns or make sense of things? In other words, we have empirical evidence that is consistent with the assumptions not always being true.

Max Planck stated that, “Anybody who has been seriously engaged in scientific work of any kind realizes that over the entrance to the gates of the temple of science are written the words: 'Ye must have faith.'” 

Do you agree these are assumptions? Would you restate any of them? Can you think of other things that scientists assume?

1 comment:

  1. An assumption that is axiomatically explicit for QM but is only implicit for QFT is that there are discernible 'systems'. The way that assumption is woven into some of the entries in your list but not into others is comparable to how that happens in most scientific contexts. Even for QFT, thinking of it as Particle Physics is ubiquitous, despite it being notionally a noisy field theory.
    The difficulty with this is, I think, that a noisy field theory does not always dimensionally reduce into a simple particle metaphysics/ontology, which I suppose is well-recognized as sometimes misleading. It is possible to formulate physics in terms of only the data that we _say_ is caused by 'particles'/'systems', with the intention that when a usefully clean dimensional reduction is possible, we can take that as a discernible system, but we do not assume ab initio that there is such (and we do not assume, for example, that whatever we discover will be perfectly point-like or otherwise localized.)
    It's not that we deny that there are systems, only that we don't take them to be so obvious that we weave them into our axioms; we take it that we must derive their existence in each case.
    Well, perhaps see the currently most recent video on my YouTube a/c @PeterMorganQF for how I work with that, where there are links to a few published articles that began this research thread. That video is 3h26m20s long, however, so first try the PDF of the slides that is also linked to there:-)

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