NEW BOOKS. 315 results of physiological research, for example, in the matter of localisation of function ; but these, it may be said, do not affect the author's contention. More to be remarked is the absence of any effort to supplement positive omissions in the original view of the working of the nervous system ; for instance, the process of inhibitory action within the system is still made only the subject of passing allusion here and there, though nothing could be of greater import for the discussion of " Experience as connected with Motor Activity ". The omissions now made are all good, being mostly of rhetorical passages, as at the end of c. vii. and throughout c. xv. (original numbering), which weakened instead of adding force to the general argu- ment of the book. This is now made still clearer than it was by the new chapter on " Animal Intelligence ". Here Dr. Calderwood does excellent service by bringing expressly into view the peculiarities of sense-endow- ment distinguishing the different classes of animals (ants, dogs, &c.), for which exceptional intelligence is claimed ; and he is thus able to account for much in their action that is too readily regarded as mysterious. His own position is, that, beyond a highly -developed and varied sensibility, nothing is needed to explain the so-called intelligence of animals but action of a mechanical type provided for by fixed connexions between sensory and motor cells in the brain and other nerve-centres ; whereas human intelli- gence (properly so called for more of human action than is generally supposed is of the merely animal kind) is only to be understood as referable to a hyperphysical entity, which somehow can be affected and operate through brain but has its being in a region wholly apart. In short, the old doctrine of Animal Automatism versus Human Conscious Intelligence, accommodated to modern physiological speech. The position, however, is far from consistently maintained. If the sensibility of animals is mere physical affection, as Dr. Calderwood would fain represent it when he has his ultimate conclusions in mind, it is difficult to see how he can interpret such facts of canine sense of wrong-doing as he still reports at p. 140 (without heed to Dr. Maudsley's doubts vivaciously expressed in MIND XV. 412). On the other hand, if, in spite of such uncertainty and wavering speech as we find, e.g., at p. 193, 4, he cannot seriously be supposed to deny to animals something analogous to our conscious experience of Sensa- tion, it is no less difficult to see how he can then be satisfied with the notion of mere " mechanism " in animals and not in their case also find it necessary to refer such subjective experience as they have (whether to be dignified as " personal " or not) to a hyperphysical region of being : which unsettles everything again. In the case of man, the plain question that will not be suppressed is, whether Dr. Calderwood thinks that the brain is called into play only when some stimulus is being received from without or impulse is being sent out from within ; and is not also somehow impli- cated in and with every mental process, high or low, so that nothing is at any time going on in the mental sphere without its proper cerebral concomi- tant. If he does so think, it is perhaps enough to say that he will hardly win credit at this time of day with either psychologist and physiologist, on the one hand, or with philosopher, on the other. Alike in regard to phe- nomenal facts, subjective and objective, and from the point of view of metaphysical interpretation, the kind of dualism which he seeks to revive gives little rest to the sole of the foot The Unity of Nature. By the DCKE OF ARGYLL, Author of The Reign of Law, <kc. London : Strahan, 1884. Pp. xv. 571. The author, having intended to follow up the chapter on "Law in Politics " in his Reign of Law (1866) with a concluding chapter on " Law in Christian Theology " which should involve a reference to some of the