The Physical Basis of Mind. George Henry Lewes
CHAPTER IV. CONSCIOUSNESS AND UNCONSCIOUSNESS. 211
CHAPTER V. VOLUNTARY AND INVOLUNTARY ACTIONS.
CHAPTER VI. THE PROBLEM STATED.
CHAPTER VII. IS FEELING AN AGENT?
PROBLEM IV. THE REFLEX THEORY.
CHAPTER I. THE PROBLEM STATED.
CHAPTER II. DEDUCTIONS FROM GENERAL LAWS.
CHAPTER III. INDUCTIONS FROM PARTICULAR OBSERVATIONS.
CHAPTER IV. NEGATIVE INDUCTIONS.
PROBLEM I.
THE NATURE OF LIFE.
“La Physiologie a pour but d’exposer les phénomènes de la vie humaine et les conditions d’où ils dépendant. Pour y arriver d’une manière sûre, il faut nécessairement avant tout déterminer quels sont les phénomènes qu’on désigne sous le nom de vie en général. C’est pourquoi la première chose à faire est d’étudier les propriétés générales du corps qu’on appelle organiques ou vivans.”—Tiedemann, Traité de Physiologie de l’Homme, I. 2.
“Some weak and inexperienced persons vainly seek by dialectics and far-fetched arguments either to upset or establish things that are only to be founded on anatomical demonstration and believed on the evidence of the senses. He who truly desires to be informed of the question in hand must be held bound either to look for himself, or to take on trust the conclusions to which they who have looked have come.”—Harvey, Second Dissertation to Riolan.
THE NATURE OF LIFE.
CHAPTER I.
THE PROBLEM STATED.
1. Although for convenience we use the terms Life and Mind as representing distinct orders of phenomena, the one objective and the other subjective, and although for centuries they have designated distinct entities, or forces having different substrata, we may now consider it sufficiently acknowledged among scientific thinkers that every problem of Mind is necessarily a problem of Life, referring to one special group of vital activities. It is enough that Mind is never manifested except in a living organism to make us seek in an analysis of organic phenomena for the material conditions of every mental fact. Mental phenomena when observed in others, although interpretable by our consciousness of what is passing in ourselves, can only be objective phenomena of the vital organism.
2. On this ground, if on this alone, an acquaintance with the general principles of structure and function is indispensable to the psychologist; although only of late years has this been fully recognized, so that men profoundly ignorant of the organism have had no hesitation in theorizing on its highest functions. In saying that such knowledge is indispensable, I do not mean that in the absence of such knowledge a man is debarred from understanding much of the results reached by investigators, nor that he may not himself make useful observations and classifications of psychological facts. It is possible to read books on Natural History with intelligence and profit, and even to make good observations, without a scientific groundwork of biological instruction; and it is possible to arrive at empirical facts of hygiene and medical treatment without any physiological instruction. But in all three cases the absence of a scientific basis will render the knowledge fragmentary and incomplete; and this ought to deter every one from offering an opinion on debatable questions which pass beyond the limit of subjective observations. The psychologist who has not prepared himself by a study of the organism has no more right to be heard on the genesis of the psychical states, or of the relations between body and mind, than one of the laity has a right to be heard on a question of medical treatment.
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,