In this post, I will deal with three additional anomalies, possible exceptions to the NSIS principle (No Substance in a Substance): (i) manufacturing organisms from scratch, (ii) borderline cases between organisms and communities, and (iii) transitional forms in evolution.
- Manufacturing living organisms from scratch
If Hylomorphism is true, it should be impossible to manufacture a living organism from inorganic materials, as in a 3D printer or a Star Trek transporter. A living organism cannot exist without the imposition of a substantial form on appropriate matter, and the power to impose living forms is peculiar to living organisms. If life was generated from non-life a billion years ago or so, this would have required the action of specialized substances with the power of engendering life. These substances or coordinated groups of substances would have taken up much of the earth’s surface, perhaps even much of the solar system. If that’s right, then it’s probably impossible in principle to re-create in this region of the cosmos the sort of conditions needed for abiogenesis.
We can obviously manufacture nanorobots. We might even be able to create self-replicating robots (von Neumann machines). But robots are not substances. They lack per se unity. Metaphysically speaking, they are mere heaps of components. Consequently, they cannot be sentient or rational. They cannot truly understand, know, deliberate, experience, decide, or converse. They can only be built so as to emulate these activities.
2. Colonies vs multicellular organisms
There are some microorganisms, like bacteria, algae, and slime molds, that are able to create and sustain mutually beneficial communities or colonies, with a certain degree of specialization of function or division of labor. The boundary line between such communities and simple multi-cellular organisms is an apparently fuzzy one. Some of these phenomena might constitute another exception to NSIS. As in the cases of cloning and conjoined twins, in these cases the substances involved would all belong to the same infima species. The community might have its own substantial form, while each of the members has a form that is a proper part of the common form.
3. Transitional forms in evolutionary history
Here I am drawing on some recent work by Daniel DeHaan at Oxford (although DeHaan does not consider the coincident-substances solution that I propose). As background, I am going to assume that Stephen Jay Gould’s model of punctuated equilibrium is correct: that nearly all organisms belong to well-populated, long-lasting, and stable specific populations. The transitions from one species of this kind to another consists of a relatively small, short-lived, and unstable transitional population. Here is my suggestion: a typical member of the transitional population actually consists of two coincident substances, one belonging to each species.
Each of the two coincident substances would have its own substantial form. Acts of procreation within the transitional population can produce offspring belonging to either or to both of the species. Eventually, a sub-population consisting entirely of members of only the new species separates from the rest and gains a selective advantage. In short order, the transitional population disappears.
How are individual variations within a species possible in the HM framework? Each species has a set of propria, and each proprium is a conditional developmental power. A proprium is conditional on some genetic information in one of the chromosomes. If that information is present, then the proprium directs the development process to produce the appropriate feature. The set of propria of a species define a function from genotypes to phenotypes. For each species, there is a specific domain of genotypes, the genotypes on which the species’ propria are defined.
When two possible species (evolutionary equilibria) are adjacent, their genotypical domains overlap. It is possible an organism to have a genotype that belongs to two such adjacent domains. In such a case, it would be impossible to tell by a narrow set of observations whether the organism belongs to one species or the other, or to both at once. Nonetheless, there will be an ontological fact of the matter as to the number and species of the organism’s substantial forms, a fact that would reveal itself in the possible viable offspring of the organism. An organism that belongs only to species S cannot have a viable offspring with a genotype outside S’s domain.
For evolution to work, we have to assume that some organisms have the causal power to generate organisms that belong to other species.
In all the cases of exceptions to NSIS, we have the threat of metaphysical over-determination. That is, there will be some matter whose existence and nature are grounded by two distinct substantial forms. This would be unacceptable if it happened too often or without some special explanation. However, the exceptions I’ve considered are not widespread, and in each case we have an explanation both for the overdetermination and for the mutual consistency of the two forms.
Given that organisms can have the power to procreate members of adjacent species, why suppose that there are any coincident, bi-specific individuals? It’s not strictly necessary to reconcile HM with evolutionary theory. However, it strikes me as at least metaphysically possible for an organism to procreate such a coincident pair, when the domains of the two adjacent species overlap.
The Analytic Thomist 