ANIMAZIONE

ANIMATION. —

I. What Biology Says

The philosophical and theological problem of animation, that is, the identification of the moment when the rational soul is infused into the body, and the still lively debate between the concept of immediate animation—i.e., at the very moment of conception—and that of mediated or delayed animation, at a much later stage of development, must find their presuppositions in the factual data of biology. It is the biologist’s task to provide these facts; to the philosopher and the theologian falls the task of their interpretation. It is quite clear that the biologist, who studies scientifically and experimentally only the material manifestation of life and biological phenomena, insofar as it alone is perceptible to our senses and measurable (spatial, weight, and temporal measurements), cannot experimentally address the problem of the soul, even if, for the vitalist biologist, it is always taken into consideration in phenomena of reactivity, adaptation, and regulation.

For the biologist, the problem of the soul is, in certain respects, identical with the problem of individuality.

The supporters of immediate animation, from the most modern current, centered on the concept of delayed animation after more or less advanced development or after birth, admit that individuality, and thus the soul, is established in the fertilized egg. Now embryology shows us how the individuality of the fertilized egg is by no means a thing irrevocably established. It is possible to divide the segmented egg in its first two cells or even at more advanced stages by tightening a loop made of an extremely thin thread (experiments on amphibians) into two parts: each part gives a complete embryo, and the egg that was supposed to give rise to a single individual produces two individuals (Spemann, Herlitzka, etc.).

In other animals, such as echinoderms and medusae, it is possible to free the various cells of a germ at the morula stage: each cell, which would have been without intervention a quarter, an eighth, a sixteenth, or a thirty-second of an individual, becomes a complete individual, albeit of smaller size due to the deficiency of material (Driesch, Zoja, etc.). This phenomenon can also occur naturally, and in many cases it is the normal condition. It is the phenomenon of polyembryony, or the development of many embryos from a single egg. In certain hymenopterans, thousands of individuals are born from a single egg (Silvestri). Even in the human species, this is not a rare phenomenon: these are cases of monochorionic twins, i.e., fetuses contained in a single chorion and nourished by a single placenta; they derive from a single egg that, for unspecified causes, has divided at a certain stage. Twins are common, but cases of triplets, quadruplets, and quintuplets are also known. They are all siblings of the same sex and resemble each other remarkably, often even in minute details (fingerprints, etc.).

But perhaps even more striking is the case of egg fusion. It has been possible (Mongold and Seidel) to fuse a germ of Triton alpestris with a germ of Triton taeniatus, and a single individual developed, a chimera of two species, which, coming from two fertilized eggs, had two fathers and two mothers.

In embryology, the problem of individuality is linked to the concept of potency, a finalistic concept that indicates the future possibility of development. The egg, it is said, is totipotent; that is, it has entirely the potential to give rise to a whole individual. When the egg divides into the first two cells, they are theoretically still totipotent, and indeed, if separated, they express this totipotency by giving rise to two individuals. But in fact, if no intervention occurs, their real potency is less than total, since they give rise only to half an individual. Why this limitation, just as the total potencies of two fused eggs are limited? For the safeguarding of individuality: the two blastomeres of an egg or the two experimentally fused eggs inhibit each other mutually, and from this reciprocal inhibition arises the harmony of an individuality. If the blastomeres of an egg are freed, the mutual inhibitions are eliminated, and the totipotencies of the individual cells come into play. If the isolation of the cells is performed at more advanced stages, these can no longer regulate themselves and give rise to new complete individuals. As development proceeds, the cells lose the material possibility of expressing their totipotency, which, theoretically, is still contained within them, probably, according to concepts of cytogenetics, in their nucleus.

The concept of reciprocal inhibition also applies to the phenomenon of fertilization. Is not the fertilized egg, the first cell of the new being, perhaps formed by the fusion of two cells, the female egg and the male spermatozoon?

Before their union, do the egg and spermatozoon also possess their totipotency? The phenomena of parthenogenesis, or the development of a virgin egg, answer this question affirmatively. In many animals, the development of eggs without the intervention of the male is a natural occurrence; indeed, in certain species, males are not even known (certain races of Artemia salina). The egg is activated by other factors of a chemical or physical nature. Experimental parthenogenesis has been widely practiced, and it has now been possible to produce parthenogenetic animals even among mammals (rabbits). Theoretically, it is a general phenomenon. Therefore, fertilization is not necessary for the emergence of an individuality.

The problem of reproduction and individuality presents other aspects of extreme interest that demonstrate how it is not limited to egg cells but, theoretically, must be referred to all the cells of an organism. There are animals, such as freshwater hydras (coelenterates), which, in addition to fertilized eggs, reproduce asexually, that is, without eggs and spermatozoa or gametes: any group of cells in the body becomes active in reproduction, a bud forms, and from it a new hydra is born. Therefore, in all the cells of the body there is totipotency, the idea of biological unity, of a higher individuality. In lower forms, where the modest differentiation is not an obstacle, such totipotency can be expressed. In higher, more differentiated forms, such totipotency can only be expressed up to a certain stage: then organic and histological differentiation becomes an insurmountable obstacle to the expression of the totipotency inherent in the protoplasm of each single cell of the organism. But where the concept of individuality becomes

The loss of various parts of the body does not compromise the rational personality of man, nor do amputations or injuries to different parts of the head and even the brain itself. A comparative study of the brain in man and other vertebrates shows that in the human brain there are parts lacking in other forms: the specific convolutions of the neocortex. This would be the instrument necessary for the soul to elaborate reasoning during life, and this nervous apparatus which enables man to achieve the highest expressions of his consciousness. Lesions in these cerebral zones erase every apparent consciousness of man. The body houses this material receptacle of the spirit; it is its well-being that determines the well-being of this [spirit], and the psychic manifestation is not so influenced, as it is influenced by external environmental conditions that act upon the body.

Science has neither the means nor the possibility of experimenting upon and analyzing the rational soul, which is immaterial; it can only identify the moment when it manifests itself with the first psychic phenomena of the child, but it is incapable of saying whether it already resides in the body before its manifestation. It is, however, able to observe how the first psychic manifestations appear with the current myelination of the nervous pathways, that is, when the specific nervous differentiation is fully realized (v.), allowing, with the myelin sheathing of the fibres, that nervous conduction which enables the perception of the sensible world, the accumulation of experiences, and, on this basis, the expression of a conscious psychic behaviour. This differentiating process, however, occurs after the birth of the child and is completed many months later. Science brings to light facts that must be considered in evaluating the problem, but it is certainly unable to solve it: they merely demonstrate how, in the study of life, not everything can be investigated and resolved with a method that is applicable only to matter.