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25 January 2020

Realism and Science

This short video by Sabine Hossenfelder makes an excellent distinction between the practice and process of doing science and Realism as a belief system. In response to the question, do you really believe that X exists, Sabine responds, "Why do you care what I believe?"


Science creates mathematical formalisms that make predictions about observations. If the observations agree with the prediction then scientists adopt the formalism as part of their worldview.

Sabine argues that the step that we take in talking about the "reality" or "existence" of such correlations between predictions and observations is not one that scientists take. It is one that philosophers take. And of course, many scientists do implicitly believe in Realism and would find it strange that anyone could doubt the Realist account of the world.

I am personally convinced by Realism as a belief system, although not by the metaphysical reductionism that many scientists add to the Realism. Metaphysical reductionism is the view that all existing things can be reduced to the lowest level of existence and that only the lowest/simplest level of existence is real. In this view no structure is real no matter how long it persists or whether is has causal potential. At the present state of knowledge, only quantum fields are real.

In my view structures are real, precisely because they persist in time (with being necessarily immutable or permanent), they can be causal agents (structure cause effects that none of their parts can even in aggregate), and they instantiate information.

In this view reductionism gives us information about real substances and antireductionism gives us information about real structures. Reductionism treats structure as unreal, and antireductionism treats substance as a mere building block. 

However, much of what scientists study is patterns of change. Most scientific formulas have time embedded in them and encapsulate change over time. This is what enables us to predict future results and to understand the past.

I believe that reality is composed of substances, structures, and regular patterns of change.

I also acknowledge that Sabine has a point about this being a belief system. The problem with this view, is that everyone has a belief system about how experience relates to reality. The default human belief system is naive realism, i.e. the view that what I experience is reality. And since experience is generated by the mind, this allows for hallucinations and false beliefs to be treated as real. Hence superstition, religion, magical thinking etc.

There may be some other belief system that is consistent with science, but I don't see it. And since we cannot realistically operate without a belief system Realism is the obvious choice. Other belief systems tend to treat technology as magic and deny the validity of science.