A friend of mine is a medical doctor with a decided philosophical bent. He solicits my assistance in helping him understand a 2021 addition to the Cambridge Elements series entitled The Metaphysics of Biology by John Dupré. I am happy to help him, thereby learning something myself about the philosophy of biology, about which I know very little. It’s actually a double deficiency since I know even less about biology. But, like my M.D. friend, I am a perpetual student. So here goes.
This exercise will require a series of posts. This one covers three sections in Part I: Metaphysical Perspectives, pp. 1-13. Double quotation marks are used to quote verbatim; inverted commas or single quotation marks are used to mention a term or phrase. Material in brackets is my insertion. Numbers in parentheses are page numbers.
A summary is inevitably an interpretive summary. Bear that in mind. I will add some critical remarks. Such remarks attempt to evaluate the claims I take the author to be making.
1 What is the Metaphysics of Biology?
We are told that metaphysics is the branch of philosophy that attempts to describe reality in the most general and abstract way. Metaphysics of biology, then, deals with the most general and abstract features of that special region of reality we call “the living world.” The author is assuming that not everything real is animate (living, dying, or dead): there is also the inanimate. He doesn’t explicitly say this, but he implies it. If so, I agree. Not everything is animate. Concrete items such as tectonic plates are not animate, and neither are such abstract items as numbers and mathematical sets. Hylozoism, then, is out, and so is panpsychism to the extent that the former supports the latter.
I hope the reader appreciates that if something is dead, then it was once alive, and so belongs to the category of the animate. The category of the inanimate, on the other hand, embraces items that are never either alive or dead.
If I may be allowed a quibble, the author’s concern is with the metaphysics of the biotic, not the metaphysics of biology, which is the study of the biotic. The biotic is both logically and temporally prior to biology since (a) the study of a subject presupposes the subject studied, and (b) life processes were transpiring long before rational animals like us made the scene. The biotic is what it is whether or not anyone studies it, whether or not there ever is any biology. Biology, the logos of bios, is something we do, a social construct; the biotic is not: it needn’t be ‘biologized.’ Whether this is a quibble or an important distinction, you are free to decide.
Now biology cannot be done a priori from the armchair: “biology proceeds not by reason [a priori] but by observation and experiment [a posteriori].” (2) I take it that everyone will agree with that; biology is an empirical science. The author appears to conclude that the same goes for the metaphysics of biology: it proceeds by observation and experiment. In fact, he appears to conclude that all metaphysics must proceed in this way, in a manner “more or less continuous with [empirical, natural] science.” The author thus advocates “a naturalistic or scientific metaphysics.” Both science and naturalistic metaphysics “draw essentially on experience.” This continuity thesis is far from obvious; Edmund Husserl, for one, would reject it. The thesis is however reasonable, so let’s play along with it.
But now the question arises whether “a metaphysics specifically of biology [biotic reality] makes any sense.” It would clearly make sense if vitalism were true. Vitalism is the view that holds “living things to be made of, or partly made of, something quite distinct from ordinary matter.” (3) But vitalism is not an option these days. Or at least no one in the life sciences these days takes it seriously. There is only one world, the physical world in which everything is made of the same “physical stuff.” So, “does not the world of physics subsume that of biology?” This amounts to the question whether biological or rather biotic phenomena reduce to physical phenomena. We will see that the author eschews reductionism in favor of emergentism.
I will reformulate the question in terms of an aporetic triad the constituent propositions of which cannot all be true.
A. Natural reality divides into the biotic (living) and the abiotic (nonliving).
B. Vitalism is not an option: there is only one world and everything in it is composed of the same sort of physical stuff. (3)
C. Physics subsumes biology: biotic phenomena are reducible to the “properties, behaviour, and interactions of the smallest elements of matter.”
If (A) and (B) are true, then (C) cannot be true. Why not? Because if the biotic reduces to physical, then the biotic is not really animate (living).
As I read him, the author solves this problem by rejecting (C) while affirming (A) and (B).
2 Reduction, Emergence, and Levels of Organization
The solution to the above problem by the rejection of (C) takes the form of a doctrine of emergence. “Biological properties” are “emergent — appearing in novel ways at higher levels of organisation, so that no knowledge of the properties of constituent parts is sufficient in principle for predicting such properties.”(3)
And so our author rejects various arguments for reductionism. His discussion strikes me as less than pellucid, but here is my way of putting one of the arguments he rejects:
D. “Physics is causally complete.” (4) The idea is that if we had “full knowledge of the laws governing the behaviour” of the smallest constituents of the material world at a given time, we would be able to predict any future state of the material world.
If so, then
E. “any macroscopic objects entirely composed of these [micro] constituents will have its behaviour fully determined by these same laws.”
What is murky here is the author’s apparent conflation of ‘horizontal’ (past-to- future) causal determination with ‘vertical’ (upward as opposed to downward) causal determination. Suppose past states of the material world determine future states in accordance with the laws of nature. That is different from saying that at any given time the behavior of the micro-constituents of a thing (whether inanimate or animate) determine the behavior of the macro-thing. But let’s move on.
3 Causation, Laws, Mechanisms and Models
If emergentism is to supplant reductionism, then we need to be able to make sense of downward causation. “For if there is downward causation, causation that acts from wholes on the parts of which they are composed, then surely parts do not fully explain causally the behavior of wholes . . . .” (9)
The author uses the heart as an example. It is a whole consisting of parts including chambers, valves, arteries. It functions as a pump causing oxygenated blood to circulate through the body of an animal. From a reductionist point of view, the behavior of the heart is wholly explainable in terms of the parts and their interaction. The causation would then be bottom-up, from the interacting parts to the whole. How then does the heart differ from a non-living machine the behavior of which is fully explainable by the interaction of the parts?
The author makes the unexceptionable point that “Hearts cannot sit unused in drawers” (13) the way non-living machines can remain unused in storage without detriment to their functionality. A heart that stops pumping for even a few minutes may be fatally damaged. The author then makes a very interesting point. While there can be no contractions without chambers, it is also the case that there can be no chambers without contractions. This is because when the contractions cease, the chambers atrophy and die. “Contractions are necessary to provide the flow of oxygenated blood to the heart muscle tissue without which in a very short time it loses its capacity to function.” (13) The author then generalizes: “Such causal dependence of the entity on its activity is characteristic of all biological systems . . . .” (13, emphasis added)
The heart is an entity whose characteristic activity is to pump blood. The author accepts a dualism of entities and activities. He goes on to say that the dualism is not egalitarian in that “Activities are more fundamental” than the entities — which he will later understand as processes — that support them. To bolster this point, he bids us compare the heart to a storm. It’s a bit of a stretch, but very interesting. He means a heart functioning normally, not a heart gone haywire electrically due to atrial fibrillation.
A storm is not a thing or substance that pre-exists its activity, but that very activity itself. It is composed of air and water molecules in motion, and so we can distinguish between the stuff a particular storm is composed of and the storm without holding that there is a self-identical something — a substrate of storming if your will — that persists through the time the storm is occurring. There is no diachronically self-same thing that storms; the storm just is its storming. The matter of the storm — air, water, leaves, whatever is swept up into it — is ever-changing as the storm arises, moves from place to place and finally subsides. We could give a particular storm the name ‘Hillary’ for ease of reference and to distinguish it from a person such as Hillary Clinton whose ‘storming’ is periodic, occasional and accidental (as opposed to essential): there is no nomological necessity that Hillary Clinton be in a continuous state of emotional outburst in the way a storm must of necessity be at every time in a state of meteorological upset.
“The storm is a process that takes in bits of matter that are, for a time, parts of it. Just the same should be said of a heart or an elephant.” (13)
A striking assertion!
A couple of questions we might explore. First, are the author’s arguments for emergentism affected by the existence of totally artificially hearts? Second, if an elephant is a process, then so is a human being. Could a human being be understood adequately as a process? This is connected with the question of how emergentism in the philosophy of biology is related to emergentism in the philosophy of mind.