CHAPTER I.

PRELIMINARY.

§ 475a. The foregoing divisions of this work have dealt with different aspects of psychological phenomena, and it remains now to co-ordinate these different aspects. Standing apart as they do, they may to some appear unconnected, and to others they may appear incongruous. It will be the aim of this division to show their congruity.

At the close of the first division it was pointed out that the Science of Psychology is distinguished by its duality of nature. Dealing with psychical phenomena as exhibited in the actions of animals and men which are visibly adjusted to surrounding actions, Objective Psychology carries on its inquiries concerning the how and the why of this correspondence, by external observation, as the sciences at large do. Contrariwise, Subjective Psychology, occupying itself with states of consciousness, their characters and relations, carries on its inquiries by internal observation, and is in so far unlike all other sciences.

Objective Psychology, as the reader will remember, falls into several parts. The first treats in the most general way of the adjustments between inner and outer actions by which living creatures maintain their lives. The second, dealing more specially with these adjustments, expresses them in terms of reflex action, instinct, reason, memory, feelings, will. The third interprets them as effected by a nervous system;

and seeks to show how this nervous system is evolved by converse with the environment. Subjective Psy

chology, again, has two great divisions. The one is concerned primarily with the order of states of consciousness as observed in self, and secondarily with the connexion between this order and the order of objective agencies to which it corresponds. The other is concerned with the general relation between consciousness and existence beyond consciousness.

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The disclosure of congruities may best be carried on by successive stages. Limiting ourselves first to the conclusions constituting Objective Psychology, as set forth in the divisions entitled "General Synthesis," "Special Synthesis," Physical Synthesis," we will observe their harmonies with one another. Passing then to the "Special Analysis," we will similarly observe how the several conclusions reached in it agree among themselves. The congruity between the set of conclusions contained in the synthetical division and the set of conclusions contained in the analytical division, will then occupy us. And the final part of the comparison will exhibit the agreement between that Transfigured Realism which the "General Analysis" leads to, and the conclusions drawn in the preceding divisions.

But before pointing out these more important verifications, it will be well to point out some less important ones. In Part I., "The Data of Psychology," certain truths yielded by Biology, and corollaries from them, were set down. Sundry empirical generalizations were reached in Part II., "The Inductions of Psychology." Our first step may fitly be to observe the congruities among these. And then the congruous results arrived at in the introductory parts we may carry with us, and from time to time observe how they agree with the results reached in the subsequent parts, analytical and synthetical.

CHAPTER II.

CO-ORDINATION OF DATA AND INDUCTIONS.

§ 4756. In a chapter on the "Structure of the Nervous System" it was shown that the simplest nervous apparatus consists of an internally-placed portion of unstable nervematter, to which there comes a nerve-fibre from a place where a stimulus is received, and from which there goes another nerve-fibre to a portion of substance which contracts when excited-an afferent fibre, an efferent fibre, and a minute ganglion through which the two are centrally connected. This being an ultimate nervous arc, we saw that for the formation of a nervous system out of such nervous arcs, there requires a third fibre, communicating between the primitive nerve-centre and other centres, either of like grade or of higher grade. So that taken together, an afferent fibre, an efferent fibre, and a centripetal fibre, with the intermediate ganglion-cell or cells, constitute what may be called the unit of composition of the nervous system. The general character of the structures resulting from combination and re-combination. of units, we found to be such that all parts of the body, subject to various stimuli from the outer world, are placed in communication with one another, and with those contracting organs by which motions of all kinds are produced. And we observed how, during that evolution of the nervous system shown in the rise of great nervous

centres, these simple relations among parts become united in complex groups of relations.

In considering "The Functions of the Nervous System," we saw that forces acting on the extremities of afferent nerves, set up molecular changes which are propagated in waves to the connected ganglia, where they set up other molecular changes greater in amount; and that through centripetal and efferent nerves, the changes thus set up are brought into relation with other changes simultaneously or subsequently set up by forces acting on other external organs, and also into relation with induced changes in the muscles. Impressions of all kinds and quantities from all parts of the periphery, are conveyed to a central receiver, and from this there go impulses which end in external actions: the receiver being thus a place where it becomes possible for the changes to be brought into such juxtaposition as permits identifications, discriminations, combinations.

And then in the chapter on "Estho-physiology," several sets of evidences were united to show that "impossible as it is to get immediate proof that feeling and nervous action are the inner and outer faces of the same change, yet the hypothesis that they are so harmonizes with all the observed facts: " the implication being that the nervous structures which connect and combine what, under their objective aspects, are nervous changes, connect and combine what, under their subjective aspects, are states of consciousness.

§ 475c. From the general truths yielded by Biology as data to Psychology, we turn to the general truths which, in the next division, were grouped as "Inductions of Psychology." Those of chief moment may be summarized as follows.

The substance of Mind is in its ultimate nature inscrutable; but respecting its proximate nature we know some. thing, and may, perhaps, eventually know more. Setting