AGES OF LIFE.—From the stage of the fertilized ovum-cell to extreme old age, the individual passes through a gradual and interconnected series of transformations. Although the spirit that informs him remains immutably identical, phenomenally the individual changes, adapting himself in his organic structures, functional attitudes, and the development of his psychic activities, through a curve of evolution from the beginning of life to full manhood, and of involution from that point to whatever degree of old age he may be destined to reach; this occurs regularly according to well-defined “auxological laws.”
Viola’s law of antagonism shows how the organism, in its growth, is subject to two opposing tendencies, one of which promotes an increase in mass (ponderal development), while the other promotes morphological differentiation; the law of alternation, or of Godin, illustrates the fact that these two tendencies develop by regularly alternating with one another in successive periods of development, so that an increase in length and mass (the turgor phase) is followed by an increase in length and morphological refinement (the proceritas phase), and so on. Only through the harmonious succession and action of the two impulses can regular, normotypical development occur (v. NORMOTIPO), balanced both from the ponderal and the morphological standpoint.
Considering that the fertilized ovum-cell arises from the union of two sexual elements with opposite structures and functional characteristics, it is suggestive to think that the laws of antagonism and alternation, according to which the individual develops, are connected with the periodically alternating antagonistic predominance of the short-limbed, vegetative, mass-related characteristics proper to the ovum and of the long-limbed characteristics, directed toward relational life and morphological differentiation, characteristic of the spermatozoon.
In the succession of the stages of life, while the organism now increases its mass, as though concentrating ever more material to be worked upon, and now perfects itself through organic differentiation, the phenomenal manifestation of the laws of Viola and Godin can clearly be discerned. Their intimate mechanism operates in relation to the endocrine balance (v. ENDOCRINE, GLANDOLE, GLANDS) predominant in each phase of the individual’s life—that is, in relation to the behavior of groups or associations of endocrine glands with anabolic or catabolic action and with vegetative or relational stimulation (the law of the rhythmic and balanced activity of the two hormonal formations, morphogenetic, or of Fende). Hence, in relation to the periodically balanced predominance of one constellation (thyroid, pituitary, adrenal medulla, sexual endocrine gland) or the other (thymus, adrenal cortex, parathyroids, pancreatic islets, etc.), arise the morphological, functional, and neuropsychic characteristics of the various stages of life; and in the adult, the final harmonious balance appears as the normotype, either the megalosplanchnic, short-limbed, hypervegetative ectotype or the microsplanchnic, long-limbed, hypovegetative ectotype.
The stages of life unfold through a prenatal and a postnatal period. The first comprises the “phase of the fertilized ovum,” the first two weeks of life, with predominant development of mass (turgor); the “embryonic phase,” from the third through the ninth week inclusive, marked by intense organogenesis and morphological differentiation (proceritas); and the “fetal phase,” from the tenth week of life to birth, with further organic refinement and full development of mass (turgor).
The postnatal period comprises the individual’s entire extrauterine life; during it, the organism traverses the whole arc of life, up to the final stage granted to it by its particular hereditary biological essence, in cooperation or conflict with environmental causes capable either of allowing it to achieve the full development of its biological destiny or of breaking it prematurely.
First comes the neonatal phase (newborn), during which, over the course of two weeks, the new organism adapts to its new state of extrauterine life, regains the weight lost during the first days, perfects the instinct of sucking, and develops its thermoregulatory and vegetative mechanisms. Infancy (v.) follows in its three periods, accompanying the individual, at approximately the seventh year, childhood (v.) or pueritia; adolescence (v.), or the prepubertal age, which, between the thirteenth and fifteenth years in females and the fifteenth and eighteenth years in males, reaches a new puberty (v.). In the postpubertal or interpubertal phase proper to youth (v.), it may be said that the organism, between twenty and twenty-five years of age (according to N. Fende, not before twenty-five to thirty), has by then achieved the completion and refinement of its physical structures and the full rational development of its intelligence. From this moment onward, life, during manhood (v.) or maturity, undergoes a slowing of its evolutionary momentum, then a halt, and finally, around forty-eight to fifty years in women and fifty to fifty-five in men, a progressive decline which, old age (v.) and decrepitude, ends in death.
This is the course of life in its entirety, to which the figure of a parabola may be applied, with an ascending, evolutionary phase and a descending, involutionary phase, both with respect to the organic aspect and to the vegetative and relational vital functions, as well as to the higher manifestations of intelligence. While the substance of the phenomenon remains the same, the attributes of the nomenclature and, within certain limits, the milestones of the individual stages may vary. Thus, some designate as “infancy” the period extending from the third week of life to the end of the first year, and as “childhood” the period from the second to the tenth year, divided into early childhood and later childhood, with the division placed approximately at the sixth year. The Romans (Varro) divided life into five periods of fifteen years each (pueri, adolescentes, juniores, seniores, seues).
The stages of life, marked, as has been said, by the alternation of the turgor and proceritas phases and by the increase of vegetative and relational life, are punctuated by the appearance of particular biological, somatic, and psychic characteristics. Among the former, for example, are the successive appearance or replacement of the different types of teeth—long, cutting, or pointed teeth (incisors, canines), or broad, flat teeth (molars)—from milk teeth to permanent teeth; among the latter, the predominant development of instinctive-affective or intellectual-volitional faculties, and the predominance of mental development in the form of evasive or imitative animistic sensory activity, extroverted and purposive activity, introverted and individualistic intuitive activity, or more fully rational activity.
An educator who ignores the somatic, functional, and mental characteristics proper to the individual stages of life is considered incapable of truly intelligent work.
From the purely ethical point of view, the influence exerted by age upon human acts is notable, especially in the so-called critical ages. For the relevant observations V. FANCIULLEZZA; PUBERTÀ; VECCHIAIA; VIRILITÀ.
Notes: N. Fende, Le doblezze di costituzione, Rome 1928; id., Crescenza e ortogenesi, Milan 1936; id., La scienza moderna della persona umana, there 1947; C. Midulla, La crisi pubertale, there 1938, pp. 12–14; M. Barbera, Ortogenesi e biotipologia, Rome 1943. Giuseppe de Nismo