AGE OF LIFE.- From the stage of the fertilized egg-cell to extreme old age, the individual passes through a gradual and interconnected series of transformations. Even within the immutable identity of the spirit that sums it up, phenomenally the individual varies, adapting in organic structures, in functional attitudes, in the unfoldings of its 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 it will be granted to reach; this regularly according to well-determined "auxological laws."
Viola's law of antagonism shows how the organism, in its growth, is subject to two opposing tendencies, one of which promotes the growth of mass (weight development), the other of morphological differentiations; Godin's law of alternations illustrates the fact that the two aforementioned tendencies unfold by regularly alternating with each other in successive periods of development, so that an increase in length and mass (phase of turgor) is followed by one in length and morphological perfection (phase of proceritas), and so on; only from a harmonious succession and action of the two impulses can a regular normotypic development (v. NORMOTIPO) be had, balanced both on the weight and on the morphological side.
Considering how the fertilized egg-cell arises from the union of the two sexual elements of opposite structure and functional characteristics, it is suggestive to think that the laws of antagonism and alternation, according to which the individual develops, are linked to the periodic alternating antagonistic predominance of the brachyline, vegetative, mass characteristics proper to the ovum and of the longiline, oriented toward relational life, morphological differentiation characteristics proper to the spermatozoon.
In the succession of the stages of life, while the organism now increases its mass, almost concentrating for further work raw material to be elaborated, now perfects itself in organic differentiation, one clearly discerns the phenomenal manifestation of the laws of Viola and Godin, whose intimate mechanism functions in relation to the endocrine balance (v. ENDOCRINE, GLANDS) predominating in each phase of the individual's life, that is, to the mode of behavior of groups of endocrine associations with anabolic or catabolic action, with vegetative or relational stimulation (law of the rhythmic and balanced activity of the two morphogenetic hormonal sub-actions, or Fende's law). From this, in relation to the periodic balanced prevalence of one constellation (thyroid, hypophysis, adrenal medulla, endocrine sex gland) or of the other (thymus, adrenal cortex, parathyroid, pancreatic islets, etc.), derive the morphological, functional, neuropsychic characteristics of the various stages of life; the definitive harmonious equilibrium in the adult as normotype, ectype megalosplanchnic brachyline hypervegetative or microsplanchnic longiline hypovegetative.
The stages of life unfold through a prenatal and a postnatal period. The first comprises the "phase of the fertilized egg," the first two weeks of life with predominant development of mass (turgor); the "phase of the embryo," third to ninth week inclusive, fervid with organogenesis and morphological differentiation (proceritas); the "phase of the fetus," from the tenth week of life to birth, with further organic perfection and full development of mass (turgor).
The postnatal period comprises the entire extrauterine life of the individual; in it the organism traverses its entire vital parabola, down to the final stage that will be granted to it by its particular hereditary biological essence, in collaboration with or in conflict with environmental causes capable of permitting it the full development of its own biological destiny or of breaking it off before its time.
First comes the neonatal phase (newborn), in which the new organism, over the course of two weeks, adapts to the new state of extrauterine life, regains the weight lost in the first days, perfects the instinct of suckling, and its own thermoregulatory mechanisms. There follows infancy (v.) in its three periods which accompany the individual, around the seventh year, to childhood (v.) or boyhood; then adolescence (v.) or prepubescent age which, between the 13th-15th year in females and the 15th-18th in males, reaches a new particular organic equilibrium in puberty (v.). In the post-pubertal or internubilo-pubertal phase proper to youth (v.) it may be said that by now the organism, between the ages of 20 and 25 (according to N. Fende, not before 25-30) has reached the completion and perfection of its physical structures, the full rational development of its intelligence. From this moment life undergoes, in manhood (v.) or maturity, a slowing in its evolutionary momentum, then an arrest, finally, around the ages of 48-50 in women, 50-55 in men, a progressive decline which, through old age (v.) and decrepitude, flows into death.
This is the course of life in its entirety, to which the figure of the parabola applies, in an ascending evolutionary and descending involutive phase, both as regards the organic aspect and the vital functions vegetative and relational, and as regards the highest manifestations of intelligence; on the substance of the phenomenon, the attributes of nomenclature may vary and, within certain boundaries, the milestone points of the individual stages. Thus, some call "infancy" the period from the third week of life to the end of the first year, "childhood" that from the second to the tenth year, divided into first childhood and second childhood, with a cut at about the sixth year. The Romans (Varro) comprehended life in five degrees of fifteen years each (pueri, adolescentes, juniores, seniores, senes).
The stages of life, marked, as has been said, by the alternation of the phases of turgor and proceritas, of increase of vegetative and relational life, are counterpointed by the appearance of particular biological, somatic and psychic characteristics; among the former, for example, the successive appearance or replacement of the different types of teeth, long, cutting or pointed (incisors, canines), or broad and flat (molars), deciduous and permanent; among the latter, the predominant unfolding of the instinctive-affective faculties or of the intellective-volitional ones, the prevalence of mental development in sensory animistic evasive form or imitative finalistic extroverted or intuitive individualistic introverted or more fully rational.
A truly intelligent work on the part of the educator who ignores the somatic, functional, mental characteristics proper to the individual stages of life is held to be impossible.
From the purely ethical point of view the influence exercised by age in human acts is notable especially in the so-called critical ages. For the relevant observations v. FANCIULLEZZA; PUBERTÀ; VECCHIAIA; VIRILITÀ.
Bibliography5 works
Giuseppe de Nismo