Reductionism

Descartes is the poster-boy for the method of "reductionism", which I think of as "Math Envy". This is the idea that you can build up all knowledge from simple principles. These days, we pretend to start with Quantum  Mechanics, yet we are awarding Nobel Prizes for people who make "baby steps" from Quantum Mechanics to the chemistry of Hydrogen. The fact is that reductionism is dead. There is no path from "simple" to "complex". We need to start somewhere else. That's good news, since it turns out that we all know a Hell of a lot more than we thought we did.

It turns out that we can start with what we all share and what we know: the fantastic and virtually limitless capabilities of the human mind. We don't need to "boil it down" to something simpler, or "explain" it in terms of chattering neurons. We learn very little about our minds by comparing them to the "minds" of chimpanzees, cats and frogs. If we assume that our minds are "nothing but" two pounds of meat on our shoulders, we succeed in explaining almost nothing while ignoring almost everything we know about our minds from first-hand experience.

The most cogent attack on reductionism I've seen comes from Nobel Prize winner Robert Laughlin: "A Different Universe: Reinventing Physics From the Bottom Down". Laughlin is not commenting outside his field here. He has first hand experience of how we actually figure out what is going on in the invisible world of Quantum Mechanics. His point is that we infer properties of the "small" world from observations in the everyday world and not the other way around. He provides example after example of the fact that we always fail when we attempt to "explain" the whole in terms of the parts. This applies as we climb from simple to complex going from Quantum Mechanics => Physics=> Chemistry => Biology. At each new level, a whole new universe of "emergent" phenomena emerge. Laughlin makes the case that there is a natural barrier between these levels. It's not just the way humans partition the world into University departments. Each new level of complexity is characterized by chaos, non-linearity and a whole new class of organizing principles.

If Laughlin is right, this turns all of Science on its head. Since Descartes and before, the project of Science has been to break down phenomena into the simplest pieces, study the pieces and bring it all together to understand the whole. It just doesn't work [2].

I hope I'm not being unfair to Dennett in guessing that, in spite of his attempt to present himself as a knowledgeable observer of Science, Laughlin's book would be well beyond his ability to comprehend. You need to "weigh a few electrons" in the lab to get what Laughlin is talking about. There is a good reason why it takes a thousand physicists and the biggest, most expensive machine in the world to "discover" the Higgs Boson. It turns out to be exponentially difficult for Quantum Mechanics to "explain" itself in detail, let alone explain simple chemical phenomena, such as the eleven different ways water crystallizes into ice.

[1] It is often forgotten that the ability of Europeans to think in anything like a logical manner was relatively new in the 17th century.  The Moors from Spain  in the 11 the century, resulting in the rediscovery of the Greeks philosophers. Before this, Europeans were not in possession of anything we would call Mathematics or logic. It took centuries to shake off the dead hand of theology and absorb the logic of the Greeks and centuries more to advance it. Progress beyond the Greeks started with Galileo and blossomed with Newton, a contemporary of Descartes. Seen from this perspective, both Newton and Descartes were still in the thrall of "Math Envy", following from the fact that the only thing they "knew for sure" came from Greek Geometry, its axioms and proofs. At least in the popular imagination, Mathematics is the ultimate reductionist discipline.

[2] Stanford's Robert Sapolsky gives an entertaining lecture on reductionism in psychology.

[3] Hofstader provides a devastating attack on reductionism in "I Am a Strange Loop", ironically taking issue with his close friend, Daniel Denett, the poster boy for reductionism. A close read of "Strange Loop" will reveal a further irony: Hofstader takes for granted that, in reality itself, the wriggling of atoms ultimately (in principle) accounts for what we experience as "mind", except the account is irrelevant and useless. He goes to great lengths to convince us that a "higher level" way of seeing things "makes sense".

Deep down, a human brain is a chaotic seething soup of particles, on a higher level it is a jungle of neurons, and on a yet higher level it is a network of abstractions that we call "symbols."

Thus, he still clings to the idea that "out there" in the universe, physics is more "fundamental" than psychology. To let go of reductionism, one must finally accept that "emergent" phenomena are genuinely new and cannot be explained in simpler terms, even "in principle".