developed "general" theory. The text is intended for attentive readers
without special training in physics or mathematics, and its aim is "to present
the main ideas in the simplest and most intelligible form, and on the whole
in the sequence and connection in which they actually originated." Einstein
goes about this task in the right way. He does not talk about the theory, he
actually develops its characteristic features. The exposition gains in clearness
by the use of well chosen concrete illustrations, and each distinct step of the
argument is presented in a separate short section with its own caption. This
is exactly the sort of thing that the serious general reader wants. Two brief
appendices describe the Lorentz transformation and Minkowski's four-dimensional space, for readers who have a little mathematics; and the author has
provided a new appendix on the experimental confirmations of the theory.
The translator has added a portrait, a biographical note, a short bibliography,
and an index. The translation is clear, and the book is well printed.
J. E. Trevor.
Cornell University.
The following books also have been received:
The Meaning and the Problem of Philosophy. By G. R. Malkani. Amalner, Indian Institute of Philosophy.—pp. 26.
Some Modern Conceptions of Natural Law. By Marie T. Collins. Cornell Studies in Philosophy, No. 12. New York., Longmans Green and Co.,
1920.—pp. 104.
Instinct and the Unconscious. By W. H. R. Rivers. Cambridge, The University Press, 1920.—pp. viii, 252.
The Secrets of the Self. By Sheikh Muhammed Iqbal. Translated from the Persian with Introduction and Notes by Reynold A. Nicholson. London, Macmillan and Co., 1920.—pp. xxxii, 148.
Bergson and His Philosophy. By J. Alexander Gunn. With an Introduction by Alexander Mair. New York, E. P. Button.—pp. xxii, 190.
The Philosophy of Don Hasdai Crescas. By Meyer Waxman. New York, Columbia University Press, 1920.—pp. xii, 162.
The Secret of Happiness, or Salvation Through Growth. By Edmond Holmes . New York, E. P. Dutton.—pp. x, 360.
Fugitive Essays. By Josiah Royce. With an Introduction by J. Loewenberg. Cambridge, Harvard University Press, 1920.—pp. 430.
Collected Essays and Reviews. By William James . New York, Longmans, Green and Co., 1920.—pp. x, 560.
The Gateway Out of Time and Space. By Vctor A. Endersby . Denver, The Infant Press.—pp. 64.
