THE POSITION OF BIOLOGY.
3. Science is the systematic classification of Experience. It postulates unity of Existence with great varieties in the Modes of Existence; assuming that there is one Matter everywhere the same, under great diversities in the complications of its elements. The distinction of Modes is not less indispensable than the identification of the elements. These Modes range themselves under three supreme heads: Force, Life, Mind. Under the first, range the general properties exhibited by all substances; under the second, the general properties exhibited by organized substances; under the third, the general properties exhibited by organized animal substances. The first class is subdivided into Physics, celestial and terrestrial, and Chemistry. Physics treats of substances which move as masses, or which vibrate and rotate as molecules, without undergoing any appreciable change of structural integrity; they show changes of position and state, without corresponding changes in their elements. Chemistry treats of substances which undergo molecular changes of composition destructive of their integrity. Thus the blow which simply moves one body, or makes it vibrate, explodes another. The friction which alters the temperature and electrical state of a bit of glass, ignites a bit of phosphorus, and so destroys its integrity of structure, converting phosphorus into phosphoric acid.
4. The second class, while exhibiting both physical and chemical properties, is markedly distinguished by the addition of properties called vital. Their peculiarity consists in this: they undergo molecular changes of composition and decomposition which are simultaneous, and by this simultaneity preserve their integrity of structure. They change their state, and their elements, yet preserve their unity, and even when differentiating continue specific. Unlike all other bodies, the organized are born, grow, develop, and decay, through a prescribed series of graduated evolutions, each stage being the indispensable condition of its successor, no stage ever appearing except in its serial order.
5. The third class, while exhibiting all the characteristics of the two preceding classes, is specialized by the addition of a totally new property, called Sensibility, which subjectively is Feeling. Here organized substance has become animal substance, and Vegetality has been developed into Animality by the addition of new factors,—new complexities of the elementary forces. Many, if not most, philosophers postulate an entirely new Existence, and not simply a new Mode, to account for the manifestations of Mind; they refuse to acknowledge it to be a vital manifestation, they demand that to Life be added a separate substratum, the Soul. This is not a point to be discussed here. We may be content with the assertion that however great the phenomenal difference between Humanity and Animality (a difference we shall hereafter see to be the expression of a new factor, namely, the social factor), nevertheless the distinctive attribute of Sensibility, out of which rise Emotion and Cognition, marks the inseparable kinship of mental with vital phenomena.
Thus all the various Modes of Existence may, at least in their objective aspect, be ranged under the two divisions of Inorganic and Organic,—Non-living and Living,—and these are respectively the objects of the cosmological and the biological sciences.
6. The various sciences in their serial development develop the whole art of Method. Mathematics develops abstraction, deduction, and definition; Astronomy abstraction, deduction, and observation; Physics adds experiment; Chemistry adds nomenclature; Biology adds classification, and for the first time brings into prominence the important notion of conditions of existence, and the variation of phenomena under varying conditions: so that the relation of the organism to its medium is one never to be left out of sight. In Biology also clearly emerges for the first time what I regard as the true notion of causality, namely, the procession of causes,—the combination of factors in the product, and not an ab extra determination of the product. In Vitality and Sensibility we are made aware that the causes are in and not outside the organism; that the organic effect is the organic cause in operation; that there is autonomy but no autocracy; the effect issues as a resultant of the co-operating conditions. In Sociology, finally, we see brought into prominence the historical conditions of existence. From the due appreciation of the conditions of existence, material and historical, we seize the true significance of the principle of Relativity.
7. Having thus indicated the series of the abstract sciences we have now to consider more closely the character of Biology. The term was proposed independently yet simultaneously in Germany and France, in the year 1802, by Treviranus and Lamarck, to express “the study of the forms and phenomena of Life, the conditions and laws by which these exist, and the causes which produce them.” Yet only of late years has it gained general acceptance in France and England. The term Cosmology, for what are usually called the Physical Sciences, has not yet come into general use, although its appropriateness must eventually secure its recognition.
Biology,—the abstract science of Life,—embracing the whole organic world, includes Vegetality, Animality, and Humanity; the biological sciences are Phytology, Zoölogy, and Anthropology. Each of the sciences has its cardinal divisions, statical and dynamical, namely, Morphology—the science of form,—and Physiology—the science of function.
Morphology embraces—1°, Anatomy, i. e. the description of the parts then and there present in the organism; and these parts, or organs, are further described by the enumeration of their constituent tissues and elements; and of these again the proximate principles, so far as they can be isolated without chemical decomposition. 2°, Organogeny, i. e. the history of the evolution of organs and tissues.
Physiology embraces the properties and functions of the tissues and organs—the primary conditions of Growth and Development out of which rise the higher functions bringing the organism into active relation with the surrounding medium. The first group of properties and functions are called those of vegetal, or organic life; the second those of animal, or relative life.