CONTENTS.
| [PROBLEM I. THE NATURE OF LIFE.] | |
| [CHAPTER I.] | |
| PAGE | |
| The Problem stated | [3] |
| (The Position of Biology) | [4] |
| (Organisms) | [8] |
| (Vital Force) | [14] |
| (Vital Force controlling Physical and Chemical Forces) | [16] |
| [CHAPTER II.] | |
| Definitions of Life | [24] |
| [CHAPTER III.] | |
| Organism, Organization, and Organic Substance | [37] |
| (Organism and Medium) | [45] |
| (The Hypothesis of Germinal Matter) | [57] |
| (Organisms and Machines) | [67] |
| [CHAPTER IV.] | |
| The Properties and Functions | [70] |
| (Does the Function determine the Organ?) | [78] |
| [CHAPTER V.] | |
| Evolution | [89] |
| (Natural Selection and Organic Affinity) | [115] |
| (Recapitulation) | [152] |
| [PROBLEM II. THE NERVOUS MECHANISM.] | |
| [CHAPTER I.] | |
| Survey of the System, | [157] |
| (The Early Forms of Nerve-Centres), | [168] |
| (The Peripheral System), | [171] |
| (Ganglia and Centres), | [172] |
| [CHAPTER II.] | |
| The Functional Relations of the Nervous System, | [176] |
| [CHAPTER III.] | |
| Neurility, | [189] |
| (Origins of Nerve-Force), | [201] |
| (The Hypothesis of Specific Energies), | [207] |
| [CHAPTER IV.] | |
| Sensibility, | [211] |
| [CHAPTER V.] | |
| Action without Nerve-Centres, | [227] |
| [CHAPTER VI.] | |
| What is taught by Embryology?, | [237] |
| [CHAPTER VII.] | |
| The Elementary Structure of the Nervous System, | [251] |
| (Difficulties of the Investigation), | [252] |
| (The Nerve-Cell), | [258] |
| (The Nerves), | [270] |
| (The Neuroglia), | [273] |
| (The Relations of the Organites), | [278] |
| (Recapitulation), | [299] |
| [CHAPTER VIII.] | |
| The Laws of Nervous Activity | [310] |
| (The Energy of Neurility) | [311] |
| (The Propagation of Excitation) | [314] |
| (Stimuli) | [321] |
| (Stimulation) | [324] |
| (The Law of Discharge) | [326] |
| (The Law of Arrest) | [333] |
| (The Hypothesis of Inhibitory Centres) | [336] |
| (Anatomical Interpretations of the Laws) | [339] |
| [PROBLEM III. ANIMAL AUTOMATISM.] | |
| [CHAPTER I.] | |
| The Course of Modern Thought | [345] |
| [CHAPTER II.] | |
| The Vital Mechanism | [363] |
| [CHAPTER III.] | |
| The Relation of Body and Mind | [376] |
| [CHAPTER IV.] | |
| Consciousness and Unconsciousness | [399] |
| [CHAPTER V.] | |
| Voluntary and Involuntary Actions | [415] |
| [CHAPTER VI.] | |
| The Problem stated | [431] |
| [CHAPTER VII.] | |
| Is Feeling an Agent? | [440] |
| [PROBLEM IV. THE REFLEX THEORY.] | |
| [CHAPTER I.] | |
| The Problem stated | [467] |
| [CHAPTER II.] | |
| Deductions from General Laws | [490] |
| [CHAPTER III.] | |
| Inductions from Particular Observations | [509] |
| (Cerebral Reflexes) | [511] |
| (Discrimination) | [520] |
| (Memory) | [522] |
| (Instinct) | [522] |
| (The Acquisition of Instinct) | [536] |
| (Acquisition) | [546] |
| [CHAPTER IV.] | |
| Negative Inductions | [550] |
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.