294 NEW BOOKS. unity of consciousness requires us to assert in psychology only as a "problematical conception ; ' the existence of the soul as "immaterial sub- stance" ; and this is the desired hypothesis. The central chapter is led up to by two others (divided into three in the Table of Contents) in which the position of psychology as " phenomenology of consciousness " is defined in relation to the three divisions of philosophy proper, ri:;., (1) logic, (2) metaphysics (theoretical), (3) ethics (practical). Chapter iv. contains a scheme of classification of psychological phenomena ; the ground of divi- sion being the relation of body and mind. From the point of view of this relation the soul is to be observed in three processes : (1) " receptive," (2) "reproductive," (3) "productive" or "creative". Chapter v. gives a short account of "the aids of psychology" (physiology, &c.). The author's leading philosophical positions, indicated in the two introductory chapters and in a digression of c, iii., are derived from Lotze. ErfaJvrung und Denk< n. Kritische Grundlegung der Erkenntnistheorie. Von JOHANNES VOLKELT, Professor der Philosophic an der Univer- sitat zu Basel. Hamburg u. Leipzig : L. Voss, 1886. Pp. xvi., 556. The author, whose criticism of Kant was noticed in MIND, Vol. v. 145, now goes on to lay the foundations of his positive theory of knowledge. Theory of knowledge is, for him, " in the strictest sense, the presupposi- tionless science ". In Kant there is the presupposition that universal and necessary knowledge exists ; and in contemporary theories of knowledge there are all kinds of concealed metaphysical, logic-d and psychological presuppositions, above all the presupposition that "there is no existence outside consciousness". The problem of theory of knowledge is first to find out whether there is any objectively valid truth at all. The starting- point, therefore, must be the doubt whether anything can be known beyond the states of the individual mind. Accordingly theory of knowle<i_ subjective ; and with this subjective character is bound up its character as having no presuppositions. This means that it is a " theory of certitude ". Objective truths (if such exist) must first of all present themselves in the form of subjective knowledge. Now among the states of which the mind has immediate (subjective) certainty, there are ultimate principles with objective reference. It is found that " the objectivity of knowledge," implied in these principles, "at bottom rests on a single principle, that of the Logical, or of thinking". "The thinking self-activity of conscious carrying with it the certainty of an objective or, as the author would prefer to call it, "trans-subjective" existence, is therefore the desired basis of universally valid truth. The book is divided into eight sections : (1) The scientific Necessity of Theory of Knowledge ; (-2) Pure Experience as Principle ; (3) The Principle of logical Necessity in its universal Signification ; (4) Knowledge as Co-operation of Experience and Thought ; (5) The subjective Factors of Knowledge; (6) The Concept in its Signifi- cance for Knowledge ; (7) The Kinds and Sources of the Uncertainty of Knowledge ; (8) Concluding Considerations. Die Ethik des Utilitarismus. Von EMIL KALER (aus Graz, Steiermark). Inaugural-Dissertation x.ui Erlan^uiiL; der Doctorwiirde, eingereicht bei der philosophisehen Facultat der Universitat BaseL Hamburg u. LMP/.U; : Leopold Voss, 1885. Pp. 78. This doctoral thesis is divided into two Sections, the first dealing with "individualistic," the second with "social 1 ' Utilitarianism. From ex- perience, the author contends, it is only possible to obtain a hypothetical, not a categorical imperative. The difficulty of having a purely formal
