Few living scientists are as ambitious in their choice of problems as Stuart Kauffman. He is a polymath, with a degree in medicine and training in biochemistry, genetics, physics, philosophy and other fields. He roams across disciplinary boundaries seeking answers to the riddles that obsess him. Why is reality so beautifully structured rather than being a chaotic mess? How probable was life? Is evolution enough to explain life's origin and diversity? How does a brain make a mind? How do minds choose? Kauffman has held appointments at many institutions, notably the Santa Fe Institute, a center for complexity studies where I first met him in the 1990s. He proposed that our scientific understanding of reality is radically incomplete, and that some sort of anti-entropy, order-generating force remains to be discovered. He spelled out these ideas in his books Origins of Order (1993) and At Home in the Universe (1995). In a 1995 article for Scientific American, "From Complexity to Perplexity," and in my 1996 book The End of Science, I knocked Kauffman and others at the Santa Fe Institute, criticizing their work as possessing more style than substance. I quoted British biologist John Maynard Smith denigrating the computer simulations of Santa Fe-ers as "fact free science," and physicist Murray Gell-Mann denying that science needs "something else," an implicit rejection of Kauffman's anti-entropy force. I've been reassessing Kauffman's work lately after seeing a moving documentary about him, Thinker of Untold Dreams, by filmmaker Richard Kroehling. The film reveals how Kauffman has continued his quest for answers in spite of personal tragedies. In retrospect, I was far too hard on Kauffman. He may not have the answers yet, but he is asking the right questions, with courage and imagination. We recently had the following email exchange:

Horgan: In retrospect, were you and other leaders in complexity research, particularly those at the Santa Fe Institute, too ambitious?

Kauffman: No and Yes. We really did create a new science. It seems "fact free," as John Maynard Smith said, because we were finding not efficient cause laws, but kinds of what might be called just math or formal cause laws. E.g., criticality in random Boolean nets, in cells, weak data, brain, better data.

Horgan: What are your greatest intellectual accomplishments?

Kauffman: I don't know. Candidates:

i. Random Boolean nets as first models of complex genetic regulatory networks with order, criticality and chaos, where it now appear brains and cells are critical for lots of reasons.

ii. Theory of spontaneous emergence of collectively autocatalytic sets, not yet clearly demonstrated but Niles Lehman is getting close, and Gonen Ashkenasy has 9 peptide collectively autocatalytic set proving molecular reproduction need not be based on template replicating RNA or DNA a la RNA World and Leslie Orgel.

iii. "No entailing laws, but enablement in the evolution of the biosphere," with Giuseppe Longo, Mael Montevil, Stuart Kauffman, 2012. This is a major negative result that seems true, shows a theory of everything cannot be true as biosphere evolution is entailed by NO law, and is part of universe. This may be THE most important thing I've done, but not alone. Published elsewhere as "Prolegomenon to Patterns in Evolution," in Biosystems, 2014. Science advances by negative results. This if true is really a big one and ushers in a new pattern of explanation in biology and life, beyond Newton.

iv. Highly speculative: "Beyond the Stalemate: Conscious Mind-Body - Quantum Mechanics - Free Will - Possible Panpsychism - Possible Interpretation of Quantum Enigma," 2014. My best, best try on mind-body, a new interpretation of quantum mechanics which may not be nuts, not too far from Penrose and Hameroffs' Orchestrated Objective Reduction. If we could ever prove much of it, e.g., consciousness is sufficient for quantum measurement, I like it a lot, but highly speculative.

Horgan: Some prominent modern scientists, such as Stephen Hawking and Francis Crick, have suggested that free will is an illusion. Comment?

Kauffman: NOT a necessary forced conclusion. Free will in our normal sense means that I could have, contrary to fact, decided and done something else, so present moment could have been different. But if quantum measurement is real and indeterminate, measurement creates electron once measured as spin up or as spin down, so present could have been different. On causal closure of classical physics, present could not have been different unless god changes initial or boundary conditions acausally. Nuts. Bohm interpretation of quantum mechanics rules out above, but multiple worlds does not, von Neumann does not, Copenhagen does not, non-locality does not. I can find NO direct evidence for free will, but the quantum enigma requires it and it is possible.

Horgan: Are any scientific problems unsolvable?

Kauffman: Yes. No laws entail evolution of biosphere so we cannot solve that problem as Newton would want by differential equations for that evolution and their integration. Biology, if functions are real in biology as I argue in "Prolegomenon to Patterns," are real, they are subsets of causal consequences, e.g., heart pumps blood, its function, but makes heart sounds. Physics has only happenings, and cannot discriminate between them. If functions are ok, biology is not reducible to physics. So we may face the Pythagorean dream of a final theory, but there may be none.

Horgan: You wrote in At Home in the Universe that Darwinian evolution is "incomplete." What did you mean by that?

Kauffman: See "No entailing laws" and "Prolegamonen." Evolution creates the very possibilities into which it becomes, without "selection" "acting" to achieve the very adjacent possible opportunities into which it becomes. Same for economic evolution, we co-create the possibilities, often unknowingly, into which we are "sucked."

Horgan: Is science getting closer to solving the mystery of how life began on Earth?

Kauffman: I truly think so. RNA world and Orgel-like template replication of single stranded RNA or cousins may be right. Or my own, improved by Wim Hordijk, Mike Steel, Eors Szathmary, Roberto Serra, Niles Lehman and Nilesh Vaidya, theory of spontaneous formation of collectively autocatalytic sets, may be right, soon shown, and if in budding liposomes, synchronize the divisions of both, Serra, giving proto-cells able to evolve to some extent, Eors. RNA world via template replication could still be right too, more than one pathway to origin of life possible, que no?

Horgan: Have you read Thomas Nagel's Mind and Cosmos? If so, are you sympathetic toward his critique of evolutionary theory in particular and science in general?

Kauffman: Loved his book. He asks most of the right questions, and I so wrote him. But I don't think he has ideas of answers. Nagel's "purposeless teleology" may rest on an unrecognized anti-entropic process in the universe, in which above level of atoms, as complexity increases, e.g. molecules, grains of dust to minerals, the space of possibilities becomes ever vaster, and more sparsely populated in non-repeating ways. Maybe the universe, life, humanity and culture become complex because this anti-entropic process says "THEY CAN" as in the ergodic hypothesis in statistical mechanics, which is not causal. In short, why did life, universe and economy become complex? We need accelerating expansion of universe for free energy and "tuned constants" but those are necessary, not sufficient. The anti-entropic process may be, with others, sufficient. I am writing a new book about this.

Horgan: I recently interviewed biologist Rupert Sheldrake. Are you sympathetic toward his call for serious scientific investigation of psychic phenomena?

Kauffman: Yes, if mind is partially quantum, nonlocality is possible so psychokinesis is possible and testable, as is telepathy. We are arrogant not to look at this with open minds, pun intended. Dean Radin claims evidence, dismissed by almost all, but psychokinesis should be testable. He claims positive evidence and non-locality is obvious candidate explanation. We will never get beyond at most epiphenomenal mind with classical physics due to its causal closure. Only quantum mechanics offers a way out at present, that I can see. See history of panpsychism back to Spinoza using 17th century concepts of matter, superseded by quantum mechanics.

Horgan: I recently interviewed physicist George Ellis, and he is distressed by the recent popularity of multiverses and string theory, which he considers to be too speculative. Care to comment on the state of theoretical physics?

Kauffman: Not a physicist. But that does not stop one from worrying. 10500 string theories and a cosmic landscape? Can't write down the theory? Not testable? Pretty sad, and presumes pre-exiting background space or spacetime. Don't like. Don't like anthropic principle. We can consider evolution of laws and constants to create a more complex universe that wins, Darwin all the way down, testable by finding constants evolved.

Horgan: Are science and religion compatible?

Kauffman: Maybe, in some sense, if Penrose-Hameroff Orchestrated Objective Reduction or my "Beyond the Stalemate" ideas are right, we get a wildly panpsychist participatory universe. In such a view, measurement anywhere is associated with consciousness and responsible will, and for entangled particles a coordinated version of the above, a kind of "mind of God." but not an omnipotent, omniscient, kind God in monotheistic sense at all. I wrote Reinventing the Sacred, Basic Books 2008, in part to find a sense of God as the natural creativity of universe.

Horgan: What do you make of the antipathy toward religion expressed by Richard Dawkins and other "New Atheists?"

Kauffman: It is wonderful for them to have expressed the truth that moral behavior requires no belief in God. Morality probably evolved in Paleolithic to some extent. But to dismiss those who do believe in God, in any sense, is arrogant and useless and divisive.

Photo by Teemu Rajala, courtesy Wikimedia Commons, http://en.wikipedia.org/wiki/Stuart_Kauffman#mediaviewer/File:Stuart_Kauffman.jpg.