Again, to take another sort of variation, some feeling connected with your own body may have passed from a marginal to a focal place, even while I speak.

The expressions ‘focal object’ and ‘marginal object,’ which we owe to Mr. Lloyd Morgan, require, I think, no further explanation.  The distinction they embody is a very important one, and they are the first technical terms which I shall ask you to remember.

* * * * *

In the successive mutations of our fields of consciousness, the process by which one dissolves into another is often very gradual, and all sorts of inner rearrangements of contents occur.  Sometimes the focus remains but little changed, while the margin alters rapidly.  Sometimes the focus alters, and the margin stays.  Sometimes focus and margin change places.  Sometimes, again, abrupt alterations of the whole field occur.  There can seldom be a sharp description.  All we know is that, for the most part, each field has a sort of practical unity for its possessor, and that from this practical point of view we can class a field with other fields similar to it, by calling it a state of emotion, of perplexity, of sensation, of abstract thought, of volition, and the like.

Vague and hazy as such an account of our stream of consciousness may be, it is at least secure from positive error and free from admixture of conjecture or hypothesis.  An influential school of psychology, seeking to avoid haziness of outline, has tried to make things appear more exact and scientific by making the analysis more sharp.

The various fields of consciousness, according to this school, result from a definite number of perfectly definite elementary mental states, mechanically associated into a mosaic or chemically combined.  According to some thinkers,—­Spencer, for example, or Taine,—­these resolve themselves at last into little elementary psychic particles or atoms of ‘mind-stuff,’ out of which all the more immediately known mental states are said to be built up.  Locke introduced this theory in a somewhat vague form.  Simple ‘ideas’ of sensation and reflection, as he called them, were for him the bricks of which our mental architecture is built up.  If I ever have to refer to this theory again, I shall refer to it as the theory of ‘ideas.’  But I shall try to steer clear of it altogether.  Whether it be true or false, it is at any rate only conjectural; and, for your practical purposes as teachers, the more unpretending conception of the stream of consciousness, with its total waves or fields incessantly changing, will amply suffice.[A]

[A] In the light of some of the expectations that are abroad concerning the ‘new psychology,’ it is instructive to read the unusually candid confession of its founder Wundt, after his thirty years of laboratory-experience: 

“The service which it [the experimental method] can yield consists essentially in perfecting