An Essay Concerning Worm Understanding

An Essay Concerning Worm Understanding

Your average worm has quite a bit of worm know-how. It knows how to dig a burrow of the right width, depth, and angle; it knows how to plug up the mouth of the burrow with leaves of various shapes and sizes; it knows how to produce castings of the right vermiform architecture; it knows how to position itself in the burrow when it is dry or cold outside. It has a kind of intelligence (worm consciousness is moot).[1] Worms have been around forever, so they must be doing something right; epistemologically, they are not absolute beginners in the art of survival. But they are deficient in the sensory department: they are blind and deaf, have only a crude sense of smell and taste, and are generally oblivious of the impinging world. They can, however, feel things and sense vibrations, so they are not entirely without sensory input: they are the recipients of tactile sense-data. Still, they are afflicted with poverty-of-the-stimulus: not much goes in and it is not very rich or instructive—it doesn’t encode what they manifestly know. The only conclusion we can draw is that their know-how is a result of innate endowment; it is instinctual and inborn. Worm knowledge (“understanding”) is in the worm’s genes. It isn’t just a copy of what their senses deliver. The worm’s slate is by no means blank. Nativism is true of the worm’s world-view. Empiricism is not a plausible theory of how worms come to know things. Evidently, all of its general knowledge is innate, with tactile sense-data confined to indicating the present state of the environment, these interacting with the general innate programs or proto-cognitions. A “rationalist” philosophy of worm intelligence would thus seem recommended: it comes from within not from outside. Even Locke would agree that much worm knowledge is not derived from the senses; it is derived from the genes and hence hereditary. It is ancestrally derived, no doubt going back many millions of years. Every worm generation automatically contains the knowledge that is helpful to worm survival and reproduction. Worms don’t learnwhat they know. Their burrow know-how is passed down the generations and does not need to be acquired anew by the individual. If we started our study of animal knowledge with worms, we would be disposed to a general nativism-rationalism. The poverty of the stimulus is only too apparent (Chomsky would have a field day with worm burrowing competence, which is quite complex and generative, even “grammatical”).

What proportion of total worm knowledge is innate? We would need to assign numbers to items of knowledge in order to answer this question (how many items of knowledge does a typical worm have?). We would also do well to assign a numerical value to the importance of the knowledge in question. These are not easy tasks, but I think a rough answer can be provided: most of the important stuff is innate. It isn’t that the vast majority of worm knowledge is based on sensory learning with only a small amount deriving from the genes. Just to have a heuristic figure, let’s say nine-tenths of it is innate, and this the good stuff. Innate knowledge is the rule not the exception. If a worm lost its stock of innate knowledge, it would be finished as a viable worm; it wouldn’t know what to do with itself. Partial lack would also be pretty catastrophic. True, its tactile sense is also important (the worm couldn’t survive for long with tactile blindness), but the innate component is clearly indispensable. Now, many species on Earth evolved from primeval worms, including humans, and animals tend to conserve the features of the animals from which they evolve—species evolve from small variations in their ancestor’s phenotype and genotype. Thus, later species often have a high proportion of genes in common with even their remotest ancestors (we are said to have 70% of our genes in common with the acorn worm). The basic structure of a derived species never strays too far from the structure of its ancestor species, despite superficial differences. So, I now want to suggest a biological law: later species have the same ratio of innate to acquired knowledge as their ancestors had. This law is empirical and testable (in principle), but on a priori grounds it is reasonable to expect it to hold. According to this law, then, human knowledge (we have been getting to that) is nine-tenths innate and one-tenth acquired (I am speaking approximately). A tenth of what we know we learned through our senses, but the overwhelming preponderance of our knowledge is inborn. Nearly everything we know we already knew in the womb. Of course, we know a good deal by means of the senses, particularly with regard to history and geography; but the really important stuff—the skeleton, the cognitive background—is innate. Possibly all concepts are innate in one way or another, as well as much propositional knowledge (and know-how): the foundations of knowledge, the building-blocks, are genetically specified. It isn’t that most knowledge is “empirical” with only a small amount “rational”; the opposite is the case. This is not the impression you get from classical discussions (Plato, Descartes, Leibniz): the idea tends to be that nearly all human knowledge is admittedly acquired through the senses, with only a small residue arising from the intellect alone. But the lowly worm teaches us otherwise: nature favors the innate over the acquired. If we trace our ancestry back through the generations to worms, we will find a steady adherence to the law adumbrated above; there is no sudden leap to an animal that reversed the polarities, as it were. Evolution never switched from the ratio set up at the time of those ancestral worms (they too, of course, come from a long line of earlier organisms successively modified). There was no saltation to an unprecedented empiricist mind; minds continued to be mainly innately formed. In the case of humans, we notice the acquired knowledge more, but from a deeper perspective innate knowledge is basic and ubiquitous. We are mainly native knowers. Our senses have not taken over the task of installing knowledge from our innate endowment; it isn’t that we have become blank slates, unlike the animals that gave rise to us. That would be evolutionarily bizarre, contrary to fundamental biological principles. Other bilateral creatures (fish, lizards, monkeys) did not suddenly convert to empiricism, so why should we? No, we are all modeled on that ancient prototype and progenitor—the humble burrowing worm. We all suffer from stimulus-poverty to one degree or another, which needs to be backed up with innate systems of know-how; empiricism is unlikely to be true of us alone. Nativism is the law of the land, the basic life plan. Nature favors the rationalist philosophy. The human brain is an evolved organ conforming to earlier brains; it is therefore primarily a device for storing innately given information, skills, and habits. And isn’t this what we should expect from a Darwinian point of view—isn’t it better for the genes to build vital knowledge in rather than leaving the individual organism to do all the epistemic work itself? Why take any chances? Worms need to hit the ground (literally) running (not literally), so they had better come equipped with the know-how they are going to need; you don’t want to be learning how to construct a burrow by trial-and-error or by watching another worm do it. A Darwinian perspective thus complements the arguments of the rationalist philosophers, strengthening their position: human (and animal) knowledge is largely inborn; it is the rule not the exception. The various forms of nativism that have been defended in recent years (conceptual, linguistic, moral, folk-physical, etc.) are thus instances of a general biological law, which we might call the Law of Genetic Epistemic Preponderance (the GEP Law), or the Worm Law in honor of that suggestive species).[2]

[1] Charles Darwin’s The Formation of Vegetable Mould Through the Action of Worms is a good source of information on worms and their life-style (quiet, hidden, transforming).

[2] Darwin was impressed by the prodigious amounts of earth that are ingested by earthworms and ejected in the form of castings, thus altering Earth’s landscape. But he wasn’t so moved by the extent of their knowledge given their lack of sensory capacities; to me, they seem like epistemic prodigies, knowing so much but exposed to so little. Not the blank slate but the carved and ornamented slate. The worm is a rich repository of inborn information. Perhaps the senses evolved when organisms started to move around more; then they needed to see and hear. We are all worms in motion (no shame in that). Tubes on wheels, as it were. (The digestive apparatus is clearly vermiform.) Of course, we are very sophisticated worm-progeny, but our basic form is worm-shaped; we clearly didn’t descend from starfish or jelly fish or barnacles.