Philosophical naturalism in the sense of ruling out the supernatural as a source of knowledge is on the rise. By and large, the view that reality is natural – containing nothing supernatural – where “natural” has something to do with what science tells us there is, is found dominating the world of science. Is there any place left for religion in a world without the supernatural?
Naturalism has won
In his opening statement at The Great Debate: Has Science refuted Religion? (March 2012), the renowned cosmologist Sean Carroll made a remarkably strong case for naturalism:
“The idea that there is only one reality, that there are no separate planes of the natural and the supernatural, that there is only one material existence, and that we are part of the universe, we do not stand outside of it in any way. […] The argument is finished, the debate is over, we have come to a conclusion. Naturalism has won.” [1]
Carroll starts from a straightforward observation: in none or our university physics departments, in none of our biology or neuroscience departments etc. is there any reference to God at all. When devising explanations of the world, there is never an appeal to a supernatural realm. [2]
God as a theory
And there is a very good reason to. From a purely scientific, explanatory point of view, God is just not a good theory. Attempts to invoke God as an effective, explanatory hypothesis pertaining to the behaviour of physical reality is fraught with difficulties. Just to name a few: attributing personhood and free will to God unfortunately makes it difficult for making exact predictions, nor is it any help in retrodicting past events, which are precisely some of the qualities you are looking for in a good scientific theory. As Sean Carroll concludes elsewhere:
“[God is] on the table as a logical possibility, but not a worthy competitor to simple naturalism. We have much better explanations now.” [3]
Methodological naturalism
One could object: doesn’t science deal only with questions regarding natural phenomena, while questions about the supernatural simply fall outside the scope of science proper? Put otherwise, couldn’t we say the scientific enterprise should restrict itself to wielding a methodological naturalism, without being entitled to make any claims outside this neatly defined range of investigation?
“Every Thing Must Go. Metaphysics Naturalized”
The crucial point is: if science is not entitled to make any cognitive claims about questions which fall outside the scope of methodological naturalism, who else can?
Precisely this simple question proves to be the granite pivotal starting point of a renewed case for ontological naturalism, made by the physicist and philosopher of science James Ladyman (professor of philosophy at the University of Bristol, UK) and Don Ross (professor of economy at the University of Cape Town, South Africa). In their groundbreaking work Every Thing Must Go. Metaphysics Naturalized(2007), [4] they advocate a scientific or what they call a “naturalized” metaphysics. By this they mean a radically naturalistic metaphysics which sole legitimate task is to unify hypotheses and theories which are taken seriously by “institutionally bona fide current science”. [5]
The principle of naturalistic closure (PNC)
Every Thing Must Go is a dense and technical work, not for the faint of heart, which goes to great lengths to build a stringent methodological model which pivots around the ‘Principle of Naturalistic Closure’ (PNC). Rephrased simply: when something is an open question in science, do not add an answer to that question in your metaphysics. [6]
Fair enough, they are the first ones to admit that scientific objectivity is not the only thing which counts in life. They readily admit that whenever scientific objectivity comes into conflict with “our desire to feel at home in our ‘Lebenswelt’”, it is not the latter which must always give way. [7] But if you are interested inobjective truth, then science is the only way to go. Even if naturalism itself depends on metaphysical assumptions, those assumptions are vindicated by the success of science.
Space limitations allow me to lift only one single idea out of this treasure of complex ideas. Provocatively, Ladyman and Ross claim that the only thing which demarcates science from non-science are institutional norms. [8] As they put it:
“Since science just is our set of institutional error filters for the job of discovering the objective character of the world—that and no more but also that and no less—science respects no domain restrictions and will admit no epistemological rivals (such as natural theology or purely speculative metaphysics)” [9]
Any place left for religion?
As a result, they reject Stephen Jay Gould’s idea that science and religion can be regarded as complementary accounts of different domains of reality (the so-called model of ‘non-overlapping magisteria’ or NOMA), unless religion can be interpreted as making no factual claims. [10]
“Any fact any religion purports to establish will, if there is any evidence for it at all, be a target for scientific explanation.” [11]
In short, religions can keep on cherishing their traditions, their rituals, their way of honouring their sacred texts, drawing from their symbolic and historic value, their way of addressing “the need to feel at home in our ‘Lebenswelt’”. But when it comes to factual truth claims about reality, it is to science they should turn.
Notes
This blog post was originally published on July 30, 2015 at:
[1] See Sean Carroll, The Case for Naturalism, see at 1’20’’ ff.https://www.youtube.com/watch?v=LhSSG76R5sM
[2] Ibid. (at 7’18’’ ff.).
[3] Sean Carroll, Is ‘God’ explanatory?, lecture, The Philosophy of Cosmology, An Oxford-Cambridge Mini Series, 9-11 January 2013, see at 52’ ff. https://www.youtube.com/watch?v=ew_cNONhhKI
[4] Ladyman, J. & Ross, D., with Spurrett, D. & Collier, J., Every Thing Must Go. Metaphysics Naturalized, Oxford, Oxford University Press, 2007.
[5] Ibid., p. 29. See also p.30: “Naturalism requires that, since scientific institutions are the instruments by which we investigate objective reality, their outputs should motivate all claims about this reality, including metaphysical ones [my italics]”.
[6] On basis of this principle they defend what they call ontic structural realism. This boils down to the adagium “There are no things. Structure is all there is.” [p.130] A view of reality which they call “in principle friendly to a naturalized version of Platonism.” [p.158] It will come as no surprise that James Ladyman turns out to be a great admirer – as I am too – of the mathematical view of reality in The Road to Reality (2004) of the British mathematician and physicist Roger Penrose.
[7] Ibid., p. 5.
[8][9][10][11] Ibid., p. 28. See Gould, S., Rocks of Ages. Science and Religion in the Fullness of Life, New York, Ballantine Books, 1999.
