In an op-ed piece in The New York Times, Ferris Jabr of Scientific American kindly informs us that nothing is really alive, not even Jabr himself or his readers. Fairly verbose for a dead guy, he develops the theme at length -- not by way of giving an explicit argument for his claim, so much as by putting forward considerations intended to make it appear something other than the killer joke it seems on its face to be. The routine is familiar, even if Jabr’s thesis is a bit more extreme than that of other biological reductionists. There’s no generally agreed upon definition of life; there are borderline cases such as viruses; living and non-living things are all made up of the same kinds of particles; so… The “so” part is where these sorts of views get into trouble, because the reductionist conclusions -- let alone Jabr’s eliminativist conclusion -- don’t follow, and even Jabr doesn’t really claim to have establishedthat there is no such thing as life (as opposed to merely putting it out there as a proposal). Indeed, if the line between the living and the non-living is as blurry as Jabr alleges, one might just as well argue that everything is alive, rather than that nothing is.
That either extreme conclusion equally well “follows” from Jabr’s premises shows that something has gone wrong here. But then, denying apparently obvious distinctions is typically a mark of imprecise rather than rigorous thinking. So too is the marketing of such denials as “liberating” (as Jabr claims the denial that life exists is). As always, the “épater la bourgeoisie” rhetorical force of bizarre claims is doing at least as much work as the philosophical and scientific considerations are. The essence of life
But let’s look at the latter. Jabr begins by noting:
Since the time of Aristotle, philosophers and scientists have struggled and failed to produce a precise, universally accepted definition of life. To compensate, modern textbooks point to characteristics that supposedly distinguish the living from the inanimate, the most important of which are organization, growth, reproduction and evolution. But there are numerous exceptions: both living things that lack some of the ostensibly distinctive features of life and inanimate things that have properties of the living.
End quote. Now, while we Aristotelian-Scholastic philosophers can hardly deny that there is no “universally accepted” definition of life, we maintain that a “precise” definition of life is in fact possible. Living things, the Scholastic holds, are those which exhibit immanent causation as well as transeunt (or “transient”) causation; non-living things exhibit transeunt causation alone. Transeunt causal processes are those that terminate in something outside the cause. Immanent causal processes are those which terminate within the cause and tend to its good or flourishing (even if they also have effects external to the cause). For example, an animal’s digesting of a meal is a causal process that tends to the good or flourishing of the animal itself (though it also has byproducts external to the animal, such as the waste products it excretes). By contrast, one rock’s knocking into another is a transeunt causal process, in that it does not in any sense tend to the good or flourishing of the rock itself. (For recent exposition and defense of this characterization of life, see chapter 8 of David Oderberg’s Real Essentialism, and his paper “Synthetic Life and the Bruteness of Immanent Causation.”) Now, Scholastics distinguish between the essenceof a thing and its properties, where both terms are used in a way that is crucially different from the way they are usually used by most contemporary philosophers. One way to think of the essence of a thing is as what we capture when we give its genus and specific difference (where a “specific difference” is what differentiates one species from others in the same genus, and where “genus” and “species” are to be understood in their traditional logical, rather than biological, senses). To take a traditional example for purposes of illustration, suppose we take a human being to be a rational animal (“animal” being the genus and “rational” the specific difference). The properties of a human being (as the Scholastic uses the term “properties”) are what flow or follow from this essence, and include things like the capacity for perceptual experience, the capacity for self-movement, the ability to form concepts, and so forth. Rational animality is not the cluster of these properties, but rather that by virtue of which a thing has them. And “properties” are not any old characteristics a thing has, but only those that flow from a thing’s essence -- that is to say, those that are proper to a thing. (For exposition and defense of the Scholastic conception of essence and properties, see chapter 4 of my book Scholastic Metaphysics: A Contemporary Introduction.) From a Scholastic point of view, the problem with too much contemporary thinking about the nature of life is that it focuses on what are really properties of life (again, in the Scholastic sense of “properties”) and tries to characterize life in terms of one of these properties or a cluster of properties. Since an essence is not a property or cluster of properties (but is rather that from which properties flow), it is no surprise that the essence of life (or of anything else for that matter) comes to seem elusive. Growth, reproduction, and the like are key to understanding life, but they are not the essence of life. They are rather properties, which flow or follow from the essence. The essence is rather a matter of the capacity of a natural substance for immanent causation or self-perfective activity -- that is to say, the ability of a thing to act for the sake of its own good or flourishing.
Now one of the several reasons why we must distinguish essence and properties is that without this distinction we cannot make sense of the distinction between normal and defective instances of a kind. For example, cats are of their nature four-legged, but that does not mean that every single cat will in fact have four legs. For genetic defect or injury might deprive some cat of one or more of its legs. Four-leggedness is a property of cats in the sense that it flows from their essence, but the flow can be “blocked,” as it were. Now if instead we think of the essence of a cat as a cluster of attributes (as contemporary metaphysicians typically would), we might conclude that “being four-legged” must not really be essential to being a cat (since there are three-legged cats), and thus must not be one of the attributes in the cluster. But we would fail thereby to capture the way in which a cat’s lacking all of its four legs is abnormal in a way that (say) its failing to be grey is not. This can be captured only by seeing four-leggedness as a true property which flows from but is nevertheless distinct from the essence (which is why in aberrant cases it may not be manifested), whereas greyness is not a property of the cat at all (in the Scholastic sense) but rather what Scholastics would call a “contingent (as opposed to proper) accident” of the cat.
In the case of defining life in general, when we fail to distinguish between essence and properties we will make similar mistakes. We might conclude, for example, that the capacity for reproduction is not really essential to living things, since there are living things (e.g. mules, and organisms whose sexual organs have been damaged) which cannot reproduce. This would be to fail to see that reproduction could still be essential to life in the sense of being a property (again, something which flows from the essence) even if in some cases it doesn’t manifest itself (where such cases are to be understood as aberrant or abnormal). In general, looking for some feature that is present in absolutely every single instance -- and then concluding, when a feature isn’t always present, that it must not really be “essential” after all -- is just too crude a way of proceeding when trying to characterize life. From an Aristotelian-Scholastic point of view, contemporary metaphysicians (and contemporary biologists when wearing their metaphysician’s hats) are simply too conceptually impoverished correctly to approach questions about essence. (Obviously this raises many questions, but the usual questions are all answered in books like Oderberg’s, and mine, which were cited above.)
Borderline cases
The absence, from contemporary thinking about essence, of the distinction between substantial form and accidental form is, like the absence of the distinction between essence and properties, another source of confusion when thinking about life. Hence some readers are bound to think of computer viruses as examples of entities that are self-perfective or act for their own good or flourishing, and would thus (it might be supposed) be candidates for living things given the Scholastic account of life. But computer viruses have merely accidental forms rather than substantial forms. That is to say, unlike true substances, which have an inherent or “built-in” principle of activity (as e.g. an acorn is inherently directed toward becoming an oak), a computer virus has an externally imposed principle of operation (as e.g. the parts of a watch have no inherent tendency to tell time, but have that function only insofar as it is imposed on them externally by the watchmaker and the users of the watch). Now a living thing is a kind of substance, with a substantial form; it is inherentlydirected toward acting for its own good or flourishing rather than being so directed only by some external factor. Since computer viruses are not like that -- qua artifacts they have only accidental forms or externally imposed principles of operation -- they are not alive, even if they mimic some aspects of life. (Of course, talk of substantial form raises many questions, which I have dealt with many times. See chapter 3 of Scholastic Metaphysics for my most detailed discussion and defense of the distinction between substantial form and accidental form.)
What of real viruses? Are they alive or not? There is no such thing as “the” Aristotelian-Scholastic position on this question, since Scholastic metaphysics must be applied to such questions in conjunction with whatever the empirical facts turn out to be. (Criticisms to the effect that the Aristotelian thinks these matters can be settled from the armchair are simply aimed at a straw man.) Oderberg argues in Real Essentialism that viruses are not alive, but the Scholastic approach to the nature of life certainly doesn’t hinge on the question. In general, the significance of borderline cases is massively overstated where questions of essence are concerned.
As I argue in Scholastic Metaphysics, the reality of essences in general cannot coherently be denied, and anything that has a regular pattern of operation or activity must ipso facto have an essence. If for some substance we find it hard to determine whether it is of kind A or kind B, it will nevertheless in fact be either of kind A or B, or of some heretofore unknown kind C. It will, that is to say, in fact have an essence, whether or not we know its essence. Where natural substances are concerned, vagueness is always epistemological rather than metaphysical.
Obviously this requires argumentation -- again, see Scholastic Metaphysics, and also Oderberg’s Real Essentialism -- but the point is that for the biological reductionist merely to cite borderline or vague cases cuts no ice. Certainly it begs the question against the Scholastic -- who has independent metaphysical reasons for the claim that vagueness is epistemological rather than metaphysical -- to suggest that viruses and the like show that there is no fact of the matter about whether a thing is alive. Just as hard cases make bad law, obsession with borderline cases (which is rife in modern philosophy) makes for bad metaphysics.
Reductionism
A third element in Jabr’s position is the implicit assumption that since living and non-living things are made of the same particles, the former must differ from the latter only in degree rather than in kind. He writes:
All observable matter is, at its most fundamental level, an arrangement of atoms and their constituent particles. These associations range in complexity from something as simple as, say, a single molecule of water to something as astonishingly intricate as an ant colony. All the proposed features of life — metabolism, reproduction, evolution — are in fact processes that appear at many different regions of this great spectrum of matter. There is no precise threshold.
End quote. Now, the “no precise threshold” stuff is, like the appeal to viruses as borderline cases, an expression of the idea that the distinction between living and non-living things is inherently vague. But whereas the appeal to viruses has to do with considerations specific to that kind of entity, here the appeal is to more general metaphysical considerations. In particular, it is an appeal to the thesis that all natural objects are “really” “nothing but” fundamental particles. “Therefore” whatever is true of any natural object must (Jabr presumably holds) “really” be a truth about how fundamental particles are arranged.
We saw some time back how this assumption determines how Alex Rosenberg approaches the question of life in his book The Atheist’s Guide to Reality. We also saw, in the same post, how Rosenberg is led -- implicitly rather than explicitly in his case -- to just the sort of eliminative position vis-à-vis life that Jabr endorses. And we saw too that there are no good arguments whatsoever for that position. For there are no good arguments for the assumption that it rests on, viz. that whatever is real must “really” be “nothing but” particles and their arrangements. (See also this follow-up post on Rosenberg’s biological reductionism.) To be sure, it is often claimed that “science shows” that this is the case, but science shows nothing of the kind. Rather, the view in question -- essentially a modern riff on the atomism of Democritus and Leucippus -- is read into science and then read back out again. The Aristotelian-Scholastic position is that there are irreducible natural substances wherever there are irreducible causal powers, and where there are irreducible substances the parts of such substances -- including the particles in question -- exist in them virtually rather than actually. In that sense, the substances are, metaphysically speaking, more fundamental than the particles, not less. (For the full story, see chapter 3 of Scholastic Metaphysics.)
Now, in the Aristotelian-Scholastic tradition, the fundamental divisions in the natural world are between the inorganic and the organic, between merely vegetative forms of life (in the technical Aristotelian sense of “vegetative”) and sentient forms of life, and between sentient forms of life and the rational sort of life characteristic of human beings. If atomism or its modern variants had in fact been proved by modern science, then we would expect that none of these divisions would be problematic for the contemporary naturalist. But in fact they all remain problematic. The difficulties facing reductive accounts of the “propositional attitudes” (beliefs, desires, etc.) are well-known to philosophers of mind, as are the difficulties facing attempts to give a reductive account of “qualia.” Yet the distinction between propositional attitudes (with their characteristic intentional content) on the one hand and merely qualitative mental states on the other is, essentially, the distinction between what Aristotelians would call intellective or rational powers and mere sentience; that is to say, it marks the third of the fundamental divisions in nature affirmed by the Aristotelian. And the distinction between creatures which possess qualia and those which do not is very close to the distinction the Aristotelian traditionally draws between sentient and non-sentient forms of life; that is to say, it marks the second of the fundamental divisions in nature affirmed by the Aristotelian.
Then there is the division between the inorganic and the organic. As the atheist and naturalist philosopher Alva Noë has acknowledged: Science has produced no standard account of the origins of life.
We have a superb understanding of how we get biological variety from simple, living starting points. We can thank Darwin for that. And we know that life in its simplest forms is built up out of inorganic stuff. But we don't have any account of how life springs forth from the supposed primordial soup. This is an explanatory gap we have no idea how to bridge...
[W]e have large-scale phenomena in view (life, consciousness) and an exquisitely detailed understanding of the low-level processes that sustain these phenomena (biochemistry, neuroscience, etc). But we lack any way of making sense of the idea that the higher-level phenomena just come down to, or consist of, what is going on at the lower level…
A living cell is more than just a chemical compound, even if every part of the cell is composed of inorganic elements. A cell, after all, is alive. What we lack, as in the case of mind, is a way of understanding how life happens due to the mere combination of nonliving precursors.
End quote. In other words, how to reduce the organic to the inorganic is (hoopla over the Miller-Urey experiment and the like notwithstanding) no more evident now than it was when Galileo and Co. pushed the Aristotelian-Scholastic tradition to the margins of Western intellectual life. (I had reason to discuss Noë’s views at greater length hereand here, and questions about the origin of life at greater length here.) So, the traditional Aristotelian divisions in nature are really no closer to being dissolved today than they ever were. And there is, I maintain, no argument to the contrary that doesn’t beg all the important questions. “We ‘know’ that the older, Aristotelian metaphysics is wrong and naturalist metaphysics correct because ‘science shows’ this; and we ‘know’ that this is the correct way to interpret ‘the science’ because we ‘know’ that the older metaphysics is wrong and that a naturalist metaphysics is better.” There really is nothing more to the contemporary consensus than this kind of circular reasoning.
In any event, I defend the radically anti-reductionist, Aristotelian hylemorphist approach to understanding the natural world at length in Scholastic Metaphysics (as does Oderberg in Real Essentialism). Reductionist appeals to arrangements of particles etc. that do not respond to Aristotelian arguments merely assume precisely what is at issue, since the Aristotelian would agree with the naturalist on the scientific facts but dispute the naturalist’s interpretation of those facts. You might say that the rumors of Aristotle’s death have been greatly exaggerated (as this, and this, and this, and this, and thisall indicate). And thus so too are rumors to the effect that “nothing is truly alive.”
