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SCIENCE 



[N. S. Vol. XXX. No. 781 



sirable that we should form some preliminary 

 conception of the general theory which is to 

 prove a solvent for them all. This theory is 

 by no means difficult to state. It is that all 

 the phenomena of consciousness (the inclusive 

 title which the book bears) may be explained 

 as due to " presentations," and groups and 

 smaller and larger systems of presentations, 

 and of their present and past reactions on one 

 another. In this principle, and indeed in not 

 a few of its applications, Mr. Marshall's the- 

 ory closely resembles, and is a sort of replica 

 of, Volkmann von Volkmar, whose masterly 

 treatise (one of the most notable works on 

 psychology of the past century), in spite of 

 all the ado made by writers on pedagogy over 

 Herbart (and Volkmann is the finished prod- 

 uct of Herbartianism) is scarcely known at 

 all in this country. Volkmann, too, accounted 

 for all the psychic facts in terms of the com- 

 binations of Vorstellungen, both in the iield of 

 consciousness and " below the threshold." 

 Volkmann, too, made use of elaborate and 

 abstruse algebraic formulas to set forth the 

 forms and laws of the actions and reactions of 

 the Vorstellungen — a device which Mr. Mar- 

 shall uses sparingly (see, however, pp. Y2 ff.), 

 but helps out with more strictly architectural 

 material in the shape of geometrical diagrams. 

 Thus far considered, the theory of the 

 " systemic " nature of human consciousness, 

 although it involves not a few highly conjec- 

 tural elements, is essentially a psychological 

 affair. For presentations, like Vorstellungen, 

 are psychic facts, so far as they have any 

 existence at all. And this is to say that our 

 theory explains some psychic facts by other 

 psychic facts. But an equally important side, 

 or half, of the complete theory of Mr. Mar- 

 shall's book is what the author calls " neur- 

 urgic." These neururgic facts, which are to 

 constitute this other half of the complete 

 theory, are, of course, happenings in the hu- 

 man nervous system. As facts, they can be 

 known only by prolonged and expert and 

 purely " objective " research ; and the sciences 

 that discover and explain them are physi- 

 ological chemistry, histology, physiology, etc. 

 Now, thirty-five or forty years of devoted. 



although somewhat intermittent, study of the 

 subject has convinced the writer of this crit- 

 ical review that all the attempts hitherto made 

 to establish a scientific theory, at once precise 

 and inclusive, of the relations between the 

 " neururgic " facts and " all the psychic facts " 

 prove on examination premature and even 

 delusive. But in Chapter I., which treats of 

 Noetic Correspondences, Mr. Marshall adopts 

 a theory of complete parallelism between the 

 two classes of facts. Every fact of sentience, 

 even the unknown or the essentially unknow- 

 able, corresponds to some fact of a definite 

 neururgic character. Nowhere, however, are 

 we told what is the effective nature of this 

 alleged correspondence. 



In order to orientate ourselves the better for 

 understanding the positions taken in the later 

 chapters, let us pause a moment in the point 

 of view held in this first chapter. From this 

 point we behold two parallel lines drawn, 

 which are to include within them the entire 

 domain of the science of psychic facts. One 

 of these lines — the psychic — consists in part 

 of undoubted psychic phenomena, which are 

 established in the only way in which such 

 initial facts can be established; and this is 

 by the awareness of the subject who experi- 

 ences them. Such facts are, however, only 

 spots, more or less detached from one another, 

 in the total line. Between and surrounding 

 them, are parts of the line which consist of 

 psychic facts of which no one is ever directly 

 aware, but which have a certain claim to 

 reality because of the service they render as 

 explanatory of undoubted facts ; but the greater 

 part of this line consists of purely conjectural 

 occurrences, to which, although they are never 

 in consciousness at all, terms are given the 

 applicability of which can be verified or dis- 

 proved only by self -consciousness. Parallel 

 with this line is another — the so-called " neur- 

 urgic " — the facts of which are of a quite 

 different order, and which, as facts, are scarcely 

 touched upon by our author; but the rest of 

 this line — i. e., the most of it — is made up of 

 unverified and unverifiable conjectures. This 

 becomes a case, then, where not only is the 

 general theory conjectural (and yet of the 



