Chapter III: When Does Human Life Begin? (2)

Up to the present time we have discovered no living organism lower in grade than the cell. If life ever originated from inorganic matter, it appeared in an organized cell. The Weismann ids, biophors, and the rest, supposing they existed outside his own imagination, are not more capable of independent life than is a chromatin granule. In any event, these biophors could not have originated spontaneously in the first living being; and if they could not so have come into existence, life could never have begun. However primitive any organism is, it must be able to nourish itself and to develop into a higher specific form; but such a variety of functions supposes differentiated structure, composed of unstable chemical substances, a correlation of parts, a purposeful anticipation of ends. Inorganic substances, crystals, and the like are characteristically stable, not unstable; and these could not have been brought into the organic state on an earth burnt to a cinder and devoid of chlorophyl, which itself presupposes organic cells. Whence came also the absolutely essential form of energy, directive of vegetative life? The only possible explanation is that life was created, not evolved by a stranger miracle from a lump of lava.

We know the successive steps in the growth of the embryo from the time of fertilization to the end of gestation, but how this vital process is effected is not so evident. What we are certain of is that there is a vital principle of some kind from the beginning, and this is the matter of real importance in the present discussion. The old moralists held that this principle in the human being is at first vegetative; after a while that vegetative vital principle is expelled by a sensitive principle; and finally this sensitive soul is expelled by the rational vital principle, or human soul. St. Thomas[40] says: "Some tell us the vital acts that appear in the embyro are not from its soul, but from the soul of the mother, or from the primitive force in the semen. Both these statements are false. Vital operations, as sensation, nutrition, growth, cannot come from an extrinsic principle; therefore it must be admitted that a soul preëxisted in the embryo, nutritive at first, then sensitive, and finally intellectual." After showing that an intellectual soul cannot be evolved from lower forms, he concludes: "Therefore we say that since the generation of one thing is always the corruption of another, in man as in other animals, when a more perfect form comes in this supposes the corruption of any precedent form; so, however, that the sequent form has all perfection that was in the destroyed forms, and something in addition: and thus through many generations and corruptions the final substantial form is attained in man and other animals. This is apparent to the senses in animals generated from putrefaction. Therefore the intellectual soul is created by God at the end of human generation, and this soul is both sensitive and nutritive, all precedent forms having been destroyed."

[40] I, q. 118, a. 2, ad 2.

There is no such thing as the generation of any animal or other living being from putrefaction; but that is irrelevant. St. Thomas's argument proves conclusively that _if_ man has first a merely vegetative soul, and secondly a merely sensitive soul, which includes the power of the vegetative soul, and thirdly an intellectual soul, which does the work of all three, that this final intellectual soul is not an evolution of the first two, but a new form that replaces these after they have served their purpose and have been annihilated. It does not even attempt to prove that man really has first a merely vegetative soul, and secondly a sensitive, and lastly an intellectual soul; it supposes all this. It starts out with the erroneous Aristotelian theory and takes it for granted. The reason for this statement is that the rational substantial form requires disposed matter to work upon, and the Thomists suppose (again erroneously) that in the human embryo during the period immediately after conception there is not enough matter to be a receptacle for the rational soul.

The soul according to the Thomists, who use the Aristotelian definition, is the first entelechy of a natural organic body that has life in potency.[41] It is the determination that gives the body its specific and substantial being; the primal actuation of a body or matter, since only in matter is there a distinction between potency for substantial being and substantial actuality. An entelechy is a realization, actuality, full perfection; sight, for example, is the entelechy of the eye. This body is natural, not merely instrumental; it is energized by an immanent principle, not moved by an external force like a tool. The body is also organic; it must have organs, faculties, parts destined to perform definite functions. To say the entelechy has life in potency means that since life, or the operation of the soul, is an immanent act, there must be a receptacle within which it can be immanent, and the soul is the primal actualization of that organic body, which is in potency to produce those immanent actions in which life consists. A body might be in potency while it still has no principle of operation, or, secondly, while it has such a principle but is not using it. In the second condition the human body is in potency for life at the moment of actualization.

[41] ἡ ψυχή ἐστιν ἐντελέχεια ἡ πρώτη σώματος ψυσικοῦ ὀργανικοῦ
δυνάμει ζωὴν ἔχοντοσ (_De Anima_, ii, 1).

A form fixes a thing in its prχοντοσoper species, and the rational soul is such a form for the human body. This substantial form is the completion, perfection, in operability and existence, of the matter that receives it. It is the formal cause of man, not the efficient cause, although it is the efficient cause of subsequent vital operations. An efficient cause makes something numerically different from itself by its own real and physical action; a formal cause and a material cause do not make anything different from themselves numerically, but they intrinsically constitute the effect--they are intrinsic causes.

The human soul as the substantial form virtually contains vegetative and sensory faculties, and through these lower organic capacities it informs and animates the body. That form, together with the matter, the body, does the vital acts of the composite human nature. The rational soul enters the body at the beginning, and first uses its vegetative faculty until the fetus is far enough advanced to be a subject for the action of the sensory faculty of the soul. Later, some time after the birth of the child, when the body is sufficiently formed, the intellectual faculty comes into use.

The nature of a vital principle is that in which it normally issues. If it issues as a rational substantial form, as in man, it was rational from the beginning. If it was not rational from the beginning, a rational principle replaced a sensory vital principle, and that sensory vital principle replaced a vegetative vital principle. The only reason for these replacements would be that the early human embryo, as has been said, lacks organization sufficient to sustain a form higher than a vegetative principle. If this were sufficient reason for deferring the advent of the rational soul, then a baby six months after birth would have no rational soul because it certainly lacks the supposedly requisite organs. However, as the rational soul is whole in each part of the adult body in the totality of its essence and perfection, but not in the totality of its virtue, because certain organs are lacking in particular parts of the body, it is in the embryo whole in the totality of its essence and perfection, but not in its virtue because certain organs are not yet formed, and it is thus from the moment of conception.

As to the soul itself, Kant held that the soul is not a real, but only a logical substance. The Pantheists, Transcendentalists, and Neo-Hegelians try to identify the soul with the divine consciousness. The Associationists (Hume, Davis, Höffding, Sully) say that the soul is a mere group of sensations. The Agnostics and Positivists (Locke, Herbert Spencer, James, Comte) write volume after volume on the soul to prove that they know nothing about it. Then the Materialists assert that there is no soul of any kind; that we secrete thought as a mule secretes sweat. Yet the vital operations of man are inexplicable as resultants of the physical and chemical properties of matter. There is an intrinsic energy that unifies the actions of man, directs processes, controls the tendency of organic matter to pass into the fixity of the inorganic, and effects metabolism. This intrinsic energy is the entelechy, substantial form, or what is popularly called the soul.

In any organic body there is a formal principle. We know that there are activities that proceed from organic bodies, and a formal principle of such activity is a substantial entity whence the organism derives basically its own kind of action, which determines and orders the activity. There are acts of perception in animals such that an external object becomes so internal to the organism of these animals that it is known by one expressed and immanent image, not only as something objectively existing but as good or hurtful to the perceiving animal. The innate and elicited appetites by which the animal tends toward or away from the object are recognized, as are the spontaneous motions which are directed by that knowledge. There must be a principle whence these actions proceed, and this is either an accident of matter or something substantial. It is not an accident of matter, because action can never arise from an accident; it must proceed from a substance. If you say this principle whence these actions arise is not an accident of matter, but matter itself, you would have an extended, composite, inert mass acting; but even if such thing could act, it could never effect a simple immanent image of an object or group of objects external to itself.

No mere machine can build up itself, can make any remote approach to metabolism as an organized body can; and the principle of this immanent action is not matter itself, because it uses, makes, subordinates matter to itself. That principle is positively one, not one by continuity as matter is. Matter as in a crystal grows by mere aggregation, an organism grows by assimilation; a crystal loses force in formation and growth, an organism accumulates force.

The theory that denies the existence of this formal principle does not explain the phenomena of life in organic beings. Uniformity of tendency toward an end is not a characteristic of mere matter; neither is a harmonious interaction of parts, nor the dependence of parts on the unit, nor motion, nor the reproduction of the species.

Moreover, most of the greatest physical scientists strongly maintain that there must be a formal substantial principle in all living things. Among these are Wallace, Nägeli, Askenasy, Preyer, Fechner, Agassiz, von Baer, E. de Beaumont, Blanchard, A. Braun, Brongniart, Bronn, Burmeister, Delff, Milne-Edwardes, Flourens, Goeppert, Griesbach, Heer, Koelliker, Mivart, Quatrefages, Quenstedt, Spiers, Volger, R. Wagner, Liebig, and Joseph Hyrtl.

The formal principle which coexists with matter in the organic body is really though not perfectly distinguished from matter. A formal principle which is necessary for sensation should be either perfectly simple, or at the least so one that its parts together make up one essence: matter, however, cannot have such unity, and as a consequence the formal principle must be distinct from matter. Anything is like its operation, and the parts of any sensitive activity always result in an activity that is essentially one. If we touch a table, by that single touch we at once know that the object is one, wooden, hard, angular, smooth, extended, and so on, and we also know that one subject perceives all these varied qualities. One eye can convey knowledge at once of a thousand objects miles apart, and these objects can be brought into one perception only by a simple subject. An extended complex subject like matter would get one impression (if it could perceive any impression) on one side, one on another, and so on, but it could not unite these.

The formal principle which is in organic bodies is a true substantial form, actuating the body both as to its nature and substance. Together with the body, this principle makes a being one in itself, such that the matter and the form separably are incomplete as regards operation and being. Now, a form is that principle through which anything is established in its own species; light, for example, is the form of a luminous body, heat of a hot substance. A body, however, is established in the human species by receiving a rational soul, and this soul, then, is its form. It is also a substantial form because the soul itself is a substance, not an accident dependent upon another subject. Moreover, from its union with the body another substance--man--arises, and not a thing added to a substance. Man's body is alive, therefore it is a living substance; but life in its secondary actuality is an operation; in its primary actuality it is an essence. The body is made a living substance, not from itself, but from the soul which is added to it. When the soul departs the body is no longer alive. Now, a principle which by a communication of itself determines the body in its essence and differentiates it as a living substance from everything else, is a substantial form. A substantial form, then, or a soul, exists.

The soul, however, must have disposed matter for most of its operations; it cannot exist as a substantial form _bombinans in vacuo_; but it does not need a human organism complete in all its parts as a necessary condition for its indwelling. There is organized matter enough in the first cell that comes into existence after the fusion of the germ-nuclei to hold this rational form, or soul, as perfectly as it needs to be held in this first stage of human life.

To inform the embryo any principle, whether it is the rational soul or a force derived from the parental organism, must have organs; and if organs are present, then the embryo is fit to receive the human soul, as the only objection to its presence is a supposed lack of organs. To use other principles when the human soul itself could be present would be a _multiplicatio entium sine necessitate_, which is a condition repugnant to the universal method of the Creator.

It has been said that the vital activity in the fertilized ovum does not proceed from the rational soul because, "in the first place, it results from the fusion of two vital activities, neither of which is rational; secondly, it results in the formation, by fission, and differentiation, of two distinct and separate living cells, each containing within itself a principle of vital activity. Now this principle of vital activity cannot be a rational soul, for each cell has its own principle of activity, and in man there is but one soul."

In the first place, that vital activity does _not_ result from the fusion of two vital activities neither of which is rational. It results _after_ the nuclei come together, by particular creation, and replaces their activity--the generation of the last vital force is the corruption of the first that existed in the separate nuclei, not a derivative of that first force. Again, when the embryo is in the two, four, eight cell stage, and so on, there are not two, four, eight vital principles present, but one. Substantial unity is essential to life of any kind, no matter how low its grade; and if each cell had an independent vital principle, any form of resultant life in the mass would be impossible. An aggregation has no unity of substance; there would be as many substances or natures as there are individual beings in the aggregate, no matter whether ordered or in a mob, consequently no life at all as a life.

The embryo in the two-cell stage is not made up of two independent organisms, any more than the right and left halves of an adult man are two independent organisms. The cells in the two-cell stage of the embryo are the right and left halves of the body, not two individuals, as has been proved repeatedly by biologists. Roux[42] punctured with a hot needle one of the cells in the two-cell stage of a frog embryo without killing the embryo, and it grew into a half-frog larva. Analogous results were obtained by operating in the four-cell stage. Later, Pflüger, Schultze, Enders, and Morgan corroborated the work of Roux. Newport[43] discovered this fact sixty years ago.

[42] Virchow's Archiv (1888), 114.

[43] _Phil. Trans._, 1854.

In analyzing the structure and functions of the individual cell we regard it as an independent elementary organic unit, but this view is solely a matter of convenience, almost a convention. All the billions of cell's in an adult man are inseparable parts of the single living person. No cell exists as an independent organism in multicellular animals, except the germ-cells, and these only after separation from the gland of origin. Indeed, the biological theory of heredity, already mentioned here, wherein the germ-cell is supposed to carry forward the entire heredity, is now changing toward the view which makes all the somatic cells influence the germ-cells; that is, the body-mass of cells sends on heredity through the germ-cell as the instrument. Adult organisms do not make cells _de novo_. New cells are formed by division from preëxisting cells, but some biologists think the body-cells so affect the new germ-cells as to influence heredity.

The cells are organs, nodal points, of a single formative power which pervades the mass of cells as a whole. The protoplasm of each cell is not only in direct apposition with its neighbors, but nearly all biologists are now inclining to the opinion, which Heitzmann proposed in 1873, that division of cell from cell is incomplete in nearly all forms of tissue; and that even where cell-walls are present (an exceptional condition in mammals) they are traversed by strands of protoplasm, by means of which the cells are in organic continuity. The whole body, he contended, is thus a syncytium (a mass of continuous protoplasm stippled with nuclei), with the cells as mere nodal points in an almost homogeneous protoplasmic mass. There are cell-bridges between the sieve-tubes of plants. In 1879 Tangl discovered such connection between the endosperm cells of plants, and later Gardiner, Kienitz-Gerloff, A. Meyer, and many others demonstrated that in nearly all plant tissues the cell-walls are connected by intracellular bridges. Ranvier, Bizzozero, Retzius, Fleming, Pfitzner, and many other observers have found these protoplasmic bridges in animal epithelium. In the skin of a larval salamander they are quite conspicuous. They are known to occur also in smooth muscle-fibre, in cartilage cells, in connective-tissue cells, and in some nerve-cells. Harrison found, in 1908, that in frogs the nerve-fibres develop out of these intracellular bridges. Dendy in 1888, Retzius in 1889, and Palladino in 1890 have shown that the follicle cells of the ovary are connected by protoplasmic bridges, not only with one another, but also with the ovum; and similar connection between somatic cells and germ-cells has been found in a number of plants. Thus even the germ-cell is not independent until it has actually broken away from the gland. A. Meyer holds that both the plant and animal individual are continuous masses of protoplasm, in which the cytoplasmic substance forms a morphological unit, no matter what the cell is. That opinion is not finally settled as regards the animal after the fetal stage, but it is much stronger as regards embryos. In the early stages of many arthropods it is certain that the whole embryo is at first an unmistakable syncytium. This is almost established also for Amphioxus, the Echinoderm Volvox, and other animals. Adam Sedgwick holds that it is true for vertebrates up to a late embryonic stage. Mitosis, then, is a form of growth of a mass, not a generation of new individuals.

Whether chromatin or any other element in the germ-cell be the idioplasm in which heredity inheres, differentiation is a progressive transformation, through physical and chemical changes, of the substance of the ovum, and this transformation occurs in a definite order and a definite distribution in the ovum. The changes result in a cleavage of the egg into cells, the boundaries of which sharply mark the areas of differentiation. These cells take on specific characters. In the four-celled stage of an annelid egg these four cells contribute equally to the formation of the alimentary canal and the cephalic nervous system, but only one of them, the left-hand posterior cell, gives rise to the nervous system of the trunk and to the muscles, connective tissues, and germ-cells. The relation between the four original cells, or blastomeres, and the adult parts arising from them, is not fixed, because in some eggs these relations may be artificially changed. A portion of the egg which normally would develop into a fragment of the body will, if split off from the others, give rise to an entire body of a diminished size.

Conklin says[44] that in the ascidian Styela "there are four or five substances in the egg which differ in color, so that their distribution to different regions of the egg and to different cleavage cells may be easily followed, and even photographed, while in the living condition. The peripheral layer of protoplasm is yellow and it gathers at the lower pole of the egg, where the sperm enters, forming a yellow cap. This yellow substance then moves, following the sperm nucleus, up to the equator of the egg on the posterior side, and there forms a yellow crescent extending around the posterior side of the egg. On the anterior side of the egg a gray crescent is formed in a somewhat similar manner, and at the lower pole between these two crescents is a slate-blue substance, while at the upper pole is an area of colorless protoplasm. The yellow crescent goes into cleavage cells which become muscle and mesoderm, the gray crescent into cells which become nervous system and notochord, the slate-blue substance into endoderm cells, and the colorless substance into ectoderm cells. Thus within a few minutes after the fertilization of the egg, and before or immediately after the first cleavage, the anterior and posterior, dorsal and ventral, right and left poles are clearly distinguishable, and the substances which will give rise to ectoderm, endoderm, mesoderm, muscles, notochord, and nervous system are plainly visible in their characteristic positions." Conklin followed these cells in every division until the embryo was developed, making a complete genealogy up to the ovum proper.

[44] _Heredity and Environment_, p. 123, Oxford Press.

De Vries[45] assumed that the character of each cell is determined by "Pangens" that migrate from the nucleus into the protoplasm. Driesch and Oscar Hertwig held that the peculiar development of a given blastomere is a result of its relation to the remainder of the cell-mass, an outcome of the action upon it by the whole system of cells of which it is a part. Hertwig said:[46] "Each of the first two blastomeres contains the formative and differentiating forces not simply for the production of a half-body, but for the entire organism; the left blastomere develops into the left half of the body only because it is placed in relation to a right blastomere." Wilson[47] and Driesch[48] came to the same conclusion about the time Hertwig wrote. Driesch said:[49] "The relative position of a blastomere in the whole determines in general what develops from it; if its position be changed it gives rise to something different; in other words, its prospective value is a function of its position."

[45] _Intracelluläre Pangenesis._ Jena, 1889.

[46] _Jenaische Zeitschrift_, 1892, 1.

[47] _Journal of Morphology_, 1893, 1894.

[48] _Studien_, iv, p. 25.

[49] _Ibid._, p. 39.

A discussion of this matter will be found in Wilson,[50] but the many experiments made in the study of this subject show conclusively that the cells, singly, grouped, and in mass, are a morphological unit, not an aggregation of distinct individuals. They are not, of course, absolutely homogeneous, because such a body could not have organs. The substantial form, therefore, is not confined to the first cell.

[50] _The Cell in Development and Inheritance_, pp. 413 _et seq._
New York, 1906.

The cell-mass, then, has a unity sufficient to be the receptacle of a human vital principle; again, the basic vital operation of the human body at any age is metabolism, and this is actually carried on in the first somatic cell of the embryo as in the cells of the adult man. In the development of the human body in the embryonal stage the energy of cell-division is most intense in the early cleavage stage, and this diminishes as the limit of growth approaches because further division is not needed. When that limit is attained a more or less definite equilibrium is established. Some of the cells in the fully formed body cease to divide, the nerve-cells, for example; others divide under special conditions, as the blood-cells, the connective-tissue cells, gland-cells, epithelial and muscle cells; others continue to divide throughout life and thus replace worn-out cells of the same tissue, as the Malpighian layer of the skin. Cells grow, divide, function, reproduce themselves, and so on, all through their vital activity, sustained by the material brought to them by the blood. Weismann[51] and other biologists think that the vital processes of the higher animals are accompanied by a renewal of the morphological elements in most tissues. The material is carried to the fetus in the womb by various agents, but mostly by the maternal blood after the embryo uses up the yolk; and when the fetal circulation has been established the nutritive material is taken from the maternal blood into the fetal circulation through the placenta, and then carried to the cells by the fetal circulation itself. After the child has been born the stomach and intestines take in the food. The stomach does very little with it except in a preparatory manner; the intestines further prepare it, pass it into the body, where it is again modified by other organs, and finally it is carried by the blood to the cells. The cells really use it; the other organs are the farmers, grocers, railways, and the like; the cells are the consumers. So far as the essential processes are concerned, the embryological cells act as do the adult cells.

[51] _The Duration of Life._

The first cell has contractility, protoplasmic motion; it can absorb perfectly all food-stuffs necessary for it from the deutoplasm of the ovum, and the water that passes in from without to the ovum. In a few days the embryonic cells have used up the deutoplasm and are taking up food from the maternal blood as perfectly as any adult cell does, and are exercising their function of building up and sustaining whatever part of the body they are destined for; and this with all the complicated metabolism of the adult cell. Cell metabolism is the fundamental, chief, organic act of any human body at any age. That the embryo does this impelled by the _virtus formativa_ transmitted from the parents is a mere gratuitous assumption to fit the theory that the embryonic cell lacks organic power. The fundamental organ that conserves the body in its very existence under the government of the soul is the apparatus which effects metabolism. Incessant chemico-vital change is a characteristic of all living substances, from the single cell up to the adult man; and in all cases this activity has to do with a transformation of the complex molecules which build up the protoplasm or are associated with its operations. The totality of the chemical changes, or exchanges, in living cells, the transformation of unorganized food materials so that these may be assimilated, and the chemical processes in the tissues themselves, all are metabolism. Growth and repair (anabolism) occur side by side with the destruction of elementary tissue substance (katabolism), and the duration of life rests on these processes; and all are mere cell activities. Food-stuffs (water, inorganic salts, proteids, albuminoids, carbohydrates, and fats) undergo more or less combustion or oxidation. Oxygen unites with carbon to form carbon dioxide, and with hydrogen to form water; the nitrogen of the highly complex proteid substances reappears in combination with carbon, hydrogen, and oxygen as urea, uric acid, and other compounds; and other ingesta are thus transformed through oxidation. All maintain the temperature of the body, replace outworn parts, and accomplish the body's work. Oxidation occurs to a slight extent in the blood, but the specific reactions are intracellular. Even when nothing exists but the cells and the blood, as in the beginning embryo, the cells really do the work, and they do the work as they do in the adult.

The cells also from the very beginning are the organs that make the animal heat necessary for life. Rubner[52] proved that the source of at least 90 per cent. of the animal heat in the body is a result of the chemical changes--oxidation--in the food ingested: the other 10 per cent. is caused by muscular contractions, the flow of blood, the friction of joints, and like motions. This oxidation is more active in young animals than in adults, and in each it is, of course, a cellular process.

[52] _Zeitschrift f. Biologie_, 1893, bd. 30, p. 73.

Living matter contains hydrogen, oxygen, sulphur, chlorine, iodine, fluorine, nitrogen, phosphorus, carbon, silicon, potassium, sodium, calcium, magnesium, and iron. The removal of one of these elements causes the death of the body. They must be arranged in a definite, prescribed order to constitute cellular protoplasm, and any disarrangement of this order causes intoxication, disease, or death. Hydrogen is a constant product in the putrefaction of animal matter, of animal food, and is present in the intestinal tract. Oxygen is found dissolved in water and loosely combined in blood as oxyhemoglobin. All the elements, except fluorine, combine with oxygen, forming oxides, and the process is called oxidation. The production of heat and all vital motion depend on oxidation, decomposition of matter. In the nuclei of cells there is a so-called "oxygen-carrier," a nucleo-proteid, which contains iron, and this appears to be the chief oxidizing agent in the body. Chlorine, which in hydrochloric acid is essential to digestion, is ingested as chloride, and leaves the body chiefly through the urine and sweat. Iodine is a necessary part of the thyroid gland, an indispensable vital organ. Fluorine is found in all cells. Nitrogen goes into the body combined in proteids; and phosphorus, combined in the alkalies and alkaline earths of the foods. Carbon occurs in all cells and leaves them through the lungs as carbon dioxide.

The amount of energy set in action in the body in the decomposition of any food is equal to the energy that had been expended in the synthesis of that food from its organic elements, and the liberated energy set free in the body appears as heat, work, and nervous impulse. In a plant the chlorophyl and the sun's rays combine water and the carbon dioxide of the air into sugar and free oxygen. This sugar is changed in a plant into starch, cellulose, and fat, and also, when combined with some nitrogen, into proteid. An animal eats this plant, which contains starch, cellulose, fat, and proteid, and it either adds these ingredients to its own substance or oxidizes them so as to prevent the destruction of its own substance. These are the ends of all food. Broadly speaking, plants synthesize elements; animals analyze them, reduce them into simpler bodies.

Such processes, and those of the other elements of the body, which have to do with the changing constituents of the human organism, are all cellular processes--metabolism. Hence the chief organic act of the body is metabolic; the basic organ of man is the cell. Arms, legs, heart, brain, stomach, and similar organs are secondary, though some of the latter are essential for certain operations. Now, one cell is an organ amply sufficient for metabolism, for the chief organic act of the body; hence it is a fitting receptacle for a substantial form, a soul. Therefore there is no reason why the soul may not be present in the one-cell stage of the embryo; and since there is no reason why it should not be present, but many why it should, it is present.

Conklin says:[53] "The fertilized egg of a star-fish, or frog, or man is not a different individual from the adult form into which it develops, rather it is a star-fish, a frog, or a human being in the one-celled stage. This fertilized egg fuses with no other cells, it takes into itself no living substance, but manufactures its own protoplasm from food substances; it receives food and oxygen from without and it gives out carbonic acid and other waste products; it is sensitive to certain alterations in the environment, such as thermal, chemical, and electrical changes--it is, in short, a distinct living thing, an individuality. Under proper environmental conditions this fertilized egg-cell develops, step by step, without the addition of anything from the outside except food, water, oxygen, and such other raw materials as are necessary to the life of any adult animal, into the immensely complex body of a star-fish, a frog, or a man. At the same time, from the relatively simple reactions and activities of the fertilized egg there develop, step by step, without the addition of anything from without except raw materials and environmental stimuli, the multifarious activities, reactions, instincts, habits, and intelligence of the mature animal."

[53] _Heredity and Environment._

An objection to the opinion that the soul is in the embryo from the beginning is made from a consideration of the facts that there appears to be an aptitude for life in certain animal cells and tissues after removal from the original host, or after the death of the host; and, secondly, that in other separated tissues life is undoubtedly made evident under proper conditions. Some parts of the human body can be grafted upon another human body, and human sarcomatous cells have been made to grow _in vitro_. Hair often lengthens after the death of a person, if no embalming fluid has been injected. Dr. Alexis Carrel[54] substituted a piece of a popliteal artery, taken from an amputated human leg and kept in cold storage for twenty-four days, for a part of the aorta of a small bitch, and the dog lived for four years afterward and died in parturition. Magitot of Paris, in 1911, took a piece of the cornea from an extirpated human eye, and with it replaced a part of an opaque cornea on another man, and this second man could see through the new cornea. Surgeons now remove skin, bone, and other tissues from still-born infants and accident cases, preserve these, for weeks if necessary, in petrolate and Ringer's solution in cold storage, and then graft them on patients to repair lesions in skin, bone, cartilage, or other parts of the body.

[54] _Journal of the American Medical Association_, vol. lix, n.
7, p. 523.

If these separated tissues are alive, what is the origin and nature of the life? Again, if there is a low form of life in these separated tissues, remaining after the departure of the human soul, why could not such a low form of life precede in the embryo the advent of the human soul?

What is the nature of the "life" in the parasitic sarcomatous tissue which has been seen to proliferate for a short time _in vitro_? We do not know, nor is it relevant to the question. That there is life of any kind in the cold-storage graft of bone and skin is certainly not evident; rather every evidence points to the absence of all life. When taken out of cold storage, and the ordinary forces which corrupt a dead body are permitted to work, these grafts corrupt exactly as any part of a corpse does. That there is life of any kind in these grafts is a gratuitous assumption. In cold storage they are kept ready for assimilation into the body as food may be kept. Bone and skin grafting is merely a peculiar form of assimilation. Food taken into the body through the stomach and entrails is prepared in the body and assimilated into the substance of the bones or skin or other tissues; the graft is ready for assimilation without this preparation because it is already bone or skin.

The vital principle in a man, or in anything else, is at the end, when it normally issues, of the same nature as it was in the beginning. If it is at perfection a substantial primary form, it always was such--a substantial form cannot issue from an accidental form. If the substantial form is the form of the cells in the completed organism, it was such before that organism was perfected, unless it replaced a lower substantial form; but there is, we repeat, absolutely no need for such a secondary form at the beginning. If the cells of the embryo (not the infused germ-cells, which are not the embryo) had a _forma corporeitatis_, or _cellularis_, or whatever you wish to call it, the human soul when it did come would not confer primal existence, would not be a _forma substantialis_, but an accidental form. "In proof of which," says St. Thomas,[55] "we must consider that a substantial form differs from an accidental form in this, that an accidental form does not give being simply, but such or such being; as heat does not give being simply, but heated being. So when an accidental form comes in, a thing is not said to come into existence or to be generated, simply, but to become such or such an object, or to find itself in such or such a condition. So, also, when an accidental form disappears, a thing is not said to be destroyed simply, but only to a certain degree. A substantial form, however, gives being simply; and therefore by its advent a thing is said to be generated simply, and by its recession to be destroyed simply. If, therefore, it happened that any substantial form other than the intellectual soul preëxisted in matter, by which the subject of that soul would come into actual being, it would follow that the soul would not confer being simply, and therefore would not be a substantial form; also that the coming of the soul would not be a generation simply, but only _secundum quid_--all of which is evidently false." Again, St. Thomas says:[56] "Some tell us the vital acts that appear in the embryo are not from the soul, but from the soul of the mother, or from the primitive force in the semen. Both these statements are false."

[55] I, q. 76, corp.

[56] Ia, q. 118, a. 2, ad 2.

An application of the opinion offered here--that is, that the human soul is infused at the instant of conception--to multiple and monstrous embryos offers no real difficulty. There are two kinds of human twins--those from two distinct ova and those from one ovum. Two ova may come from one or different ovaries, or even from one Graafian follicle, be fertilized at the same time and develop synchronously. If the ova are placed at some distance apart in the uterus, two placentas appear; if the ova are near each other the placentas may fuse, but their circulations do not. Each child will have its own fetal envelope.

In twins from two distinct ova there is no difficulty in seeing that the souls are placed in these in the same manner as the soul is put in the normal single embryo. When the twins come from one ovum the condition is not so simple. The oval nucleus is the essential part that goes from the maternal side, and human ova at times contain two nuclei, as occasionally hens' eggs do; a double-yoked hen's egg has two nuclei, and two nuclei have been found in a single yolk. Kölliker, Stöckel, and von Franque have observed double germinal vesicles in single human ova. In such a condition two spermatozoa could fecundate the two nuclei and the development go on as in the case of twins from distinct ova.

There is a theory which holds that homologous twins (uni-oval) can develop from a single germinal vesicle which splits into two primitive streaks and two gastrulas. According to this opinion, if the germinal vesicle divide entirely, two fetuses develop which are always of the same sex, and which resemble each other so closely in appearance that it is very difficult to differentiate them. This theory holds also that should the germinal vesicle not split fully, the lack of fission causes the various kinds of double monsters. The germinal vesicle that supposedly splits into two is not fecundated by two spermatozoa, they say, because where there is only one nucleus in the beginning, the entrance of a second spermatozoön commonly kills the ovum. This last assertion has been disproved of late.

Some followers of the splitting theory hold that double monsters arise from the union of two originally separate primitive traces (_Verwachsungstheorie_). Others say that a single primitive trace of blastoderm cleaves more or less thoroughly and makes the double monster (_Spaltungstheorie_). The earliest human double monster (Ahlfeld's case) was in the fourth week of gestation; therefore whatever is held in these theories as regards human monsters is only through analogy with lower animals.

Gerlach[57] saw bifurcation at the cephalic end of a chicken embryo sixteen hours old. In this case the first change was a broadening of the anterior end of the primitive streak; next a forked divergence appeared, and by the twenty-sixth hour the bifurcation was half as long as the undivided posterior part. Whether this was a case of two nuclei or not is not known.

[57] _U. d. Entstchungsweise der vordern Verdoppelung. Deutsch.
Archiv. f. klin. Med._, 1887.

What seems to make for the fission theory is that in non-parasitic double terata, no matter how unequally nourished or how variable in extent, the union between the halves of double monsters is symmetric, and the same part of each twin is joined. This fact is used as a reason to exclude a fortuitous growing together of dissimilar areas of cell-masses, at least in non-parasitic cases. Born,[58] in a study of fish ova, found that eggs which produce double monsters begin with a segmentation like that of the simple normal ovum. Composite spermatozoa have been observed with two and three heads and one body and tail-piece, but the significance of these abnormal cells is not known.

[58a] _U. d. Furchung des Eies bei Doppelbildungen. Breslauer
Aertzliche Zeitschrift_, 1887.

Embryos of sea-urchins in the two-cell and four-cell stages can be separated by shaking into isolated blastomeres, and the segments will grow into full though dwarfed larvae. The same division with the growth of dwarfed larvae has been made in Amphioxus, in the teleost Fundulus, in Triton, in a number of Hydromedusae and several other low forms of life. When the division is not made completely double monsters result.

Up to a certain stage of development the blastomeres of the Medusa embryo are totipotent, or capable of developing into any part of the body. The limitation of development in a particular case lies in the cytoplasm rather than in the nuclei of the cells. If frogs' eggs are fastened in abnormal positions, inverted or on the side, a rearrangement of the egg material results, wherein the nucleus and cytoplasm rise and the deutoplasm sinks. This change of axis shifts the embryo. If an egg is turned upside down in the two-cell stage, a whole embryo, or half a double embryo, may arise from each of the two blastomeres, instead of a normal half-embryo. A half-embryo or a whole dwarf may arise according to the artificial position of the blastomere. Each of the two blastomeres contains all the materials potentially for the formation of the whole body, and these materials build up a whole body or a half body according to the grouping they take on. Primarily the egg cytoplasm, in low forms of animal life, is totipotent; it has no fixed relation with the parts to which it gives rise, and may be artificially modified or differentiated. These effects, from position and traumatic dislocation, suggest explanations for teratic forms in higher animals.

Human terata are now commonly classified in four groups: (1) Hemiteratic; (2) Heterotaxic; (3) Hermaphroditic; and (4) Monstrous. Hemiterata are giants, dwarfs, persons showing anomalies in shape, color, closure of embryonal clefts, in absence or excess of digits, or like defects. The Heterotaxic group are persons whose left or right organs are reversed in position. A true Hermaphrodite would have the complete reproductive organs of both sexes, but such an individual has not been observed. There is never any question of double personality in hermaphrodites.

Terata more properly so called may be single, double, or triple; and single monsters may be autositic or independent of another fetus, or they may be omphalositic, dependent upon another which is commonly well developed and which supplies blood for both through the umbilical vessels. There are four genera of autositic single monsters, with eight species and thirty-four varieties. Of the _monstra per defectum_ the commonest are caused by a failure of closure in the embryonal medullary canal, which leaves part of the brain and spinal cord or their bony covering lacking. Some terata, as the Acephalia, have no brain or spinal cord, but they die in the fetal stage. The Anencephalia may have a spinal cord, a medulla oblongata, and parts of the basal ganglia, but the cerebral hemispheres are wanting. Such monsters are sometimes born at term and live for several days: they cry, suckle, show some reflexes and a sense of pain, and move the arms and legs.

I described the various kinds of terata in _Essays in Pastoral medicine_,[58b] and of these the most important in the matter under discussion here are the double and triple monsters. Many of the double monsters evidently were two persons. There is only one well authenticated case of a triple human monster, and this happened in Italy in 1831. It had a single broad body with three distinct heads and two necks, and was killed in delivery. There is no proof as to whether it was one or more persons. The standard of judgment in such cases as regards the presence of one or two souls in the monster is the evidence of one or more distinct consciousnesses. A monster double from the navel or breast downward (_terata anadidyma_) is, I think, one person. There was an example of a monster in this group which was divided from the foreheads downward; or better, the distinct twins were united by their foreheads only; but such a form is very exceptional. In my article on "Human Terata and the Sacraments," in _Essays in Pastoral Medicine_, in 1906, I expressed the opinion that a monster which is single to the navel and double below is composed of two persons, but I now am of the opinion that such a monster is only one person, because there is apparently only one consciousness. There are about eight cases of two-headed monsters known which were evidently two persons in each case, and several terata kata-anadidyma, divided above and below but joined at the sternum, abdomen or sacrum. Several ischiopagic twins, joined at the pelvis with the heads at the opposite ends of the double body, are grouped with either the katadidyma or kata-anadidyma. It is commonly not difficult to recognize individuality or duality of personality in monsters, but it is not easy to explain the origin of life, to point out the moment the _second_ soul enters these fused or undivided twins.

[58b] Chap. vi, p. 69. New York, 1906.

We can artificially obtain double embryos of frogs by inverting
the blastomeres in the two-cell stage.[58c] We thus get united
twins with heads turned in opposite directions, twins united back
to back like the Blazek Sisters, twins united by their ventral
sides, and double-headed tadpoles, but we have no knowledge of
how similar doubling in human monsters takes place; we must guess
vaguely from analogy. There was one soul, at least, present from
the one-cell stage of the human monster; when the second soul
is created and infused we do not know, but the moment of the
creation of this second soul has no practical significance in
this discussion.

[58c] See Wilson, _op cit._., p. 421.

The presence of certain kinds of monsters in the uterus can
be diagnosed before labor, but double monsters are mistaken
for ordinary twins. A woman who has given birth to a monster
is likely to have subsequent monstrous fetuses. Where the
intrauterine existence of a single monster is suspected the X-ray
will at times clear up the diagnosis. Women gravid with monsters
commonly abort early in pregnancy, but even united twins may go
on to term. Those monsters that offer an obstacle to delivery
by the abnormal bulk of one or the other end are mostly twins
joined above or below the navel; those joined at the middle are
easier of delivery. Monsters that are joined at the pelves are
commonly in a straight line, and may not be difficult to deliver.
Most double monsters cannot be delivered alive except by cesarean
section, and the fact that the content of the uterus is monstrous
is, as a rule, not diagnosed until it is impossible to attempt
cesarean section without killing the mother through infection.
In such a condition the double monster would, in the ordinary
medical practice, be delivered by craniotomy, exenteration,
cleidotomy, or the like operation.

The _Rituale Romanum Pauli V_[59] gives the following directions
for the baptizing of human terata:

"18. In monstris vero baptizandis, si casus eveniat, magna
cautio, adhibenda est, de quo si opus fuerit, ordinarius loci,
vel alii periti consulantur, nisi mortis periculum immineat.

"19. Monstrum, quod humanam speciem non praeseferat baptizari non
debet; de quo si dubium fuerit, baptizatur sub hac conditione;
_Si tu es homo ego te baptizo_, etc.

"20. Illud vero, de quo dubium est, una ne, aut plures sint
personae non baptizetur, donee id discernatur: discerni autem
potest si habeat unum vel plura capita, unum vel plura pectora;
tune enim totidem erunt corda et animae, hominesque distincti, et
eo casu singuli seorsim sunt baptizandi, unicuique dicendo: _Ego
te baptizo_, etc. Si vero periculum mortis immineat, tempusque
non suppetat, ut singuli separatim baptizentur, poterit minister
singulorum capitibus aquam infundens omnes simul baptizari,
dicendo: _Ego vos baptizo in nomine Patris, et Filii, et Spiritus
Sancti_. Quam tamen formam in iis solum, et in aliis similibus
mortis periculis, ad plures simul baptizandos, et ubi tempus non
patitur, ut singuli separatim baptizentur, aliis nunquam, licet
adhibere.

"21. Quando vero non est certum in monstro duas esse personas, ut
quia duo capita et duo pectora non habet distincta; tune debet
primus unus absolute baptizari, et postea alter sub conditione,
hoc modo: _Si non es baptizatus, ego te baptizo in nomine Patris,
et Filii, et Spiritus Sancti_."

[59] Tit. ii, cap. 1, nn. 18, 19, 20, 21.

Any kind of monster coming from the human womb, if it is only a head and lacks a body (Acardiacus Acormus), or is a body and lacks a head and heart (Acardiacus Acephalus), or is a Foetus Anideus, which is a shapeless mass of flesh covered with skin, should be baptized, provided _it shows signs of life_. Number 19 in the Ritual would be liable to an interpretation which is too narrow if it were not that very monstrous fetuses, which appear to a lay observer to be not human, are as a rule delivered dead. Here it may be worth while to mention that a hybrid between a human being and a lower animal is impossible. As to number 20, the rule for differentiating unity or duality of personality is not the number of heads, but the number of evident consciousnesses, and this differentiation commonly cannot be made at birth. There have been examples of two-headed monsters delivered alive, which were single as to soul because the consciousness evidently was one.