By the Author of "Daedalus"

POSSIBLE WORLDS. By J. B. S. Haldane. (Harpers.)

SINCE the appearance of his brilliant little volume, “Daedalus,” some five or six years ago, J. B. S. Haldane, the great biochemist of Cambridge, has been perhaps the most widely read speculative scientist in the world. Anyone who enjoyed “Daedalus” should know why. He is not to be classed with the “popularizers” of science, but he discusses scientific matters from a commonsense viewpoint and with a sense of humor that are far more effective than the popularizer’s art. He does not give the impression of taking the layman’s ignorance into consideration; rather, he seems to be so thoroughly the master of what he knows and to have thought so much all around every subject he chooses to discuss, that he is able to present the essential idea in a simple way. He does not lecture; he chats familiarly with the reader, leading him into strange realms of fact and possibility with no apparent effort.

“Possible Worlds” is a collection of 35 papers which have appeared in various British and American periodicals. They touch upon important points throughout the whole range of modern science and at times venture into the realms of religion and psychical research.

The title essay, which is placed near the end of the volume, represents one of Haldane’s characteristic flights into the nebulous regions of possibility. It is concerned with what many good thinkers have regarded as the basic error in human thought, and should serve, here and there, to disturb the complacency with which the “objective” world is generally accepted as the only reality. It is commonly assumed that our senses are capable of presenting enough data by which to know the world of which we are a part; but Haldane undertakes to construct other and very different worlds that could be quite as “real” as the one we accept without question. He does this in various ways, showing how the “real world” would necessarily change with different sets of data. For instance, he plays with the conception of a world that would result from data received only through the sense of hearing, and shows how an “exact science” might be built up with interpretations of sound vibrations alone. He also constructs a possible dog’s world, in which data received through the sense of smell would be of major importance.

“Our only hope of understanding the universe,” writes Haldane, “is to look at it from as many different points of view as possible. This is one of the reasons why the data of the mystical consciousness can usefully supplement those of the mind in its normal state. Now, my own suspicion is that the universe is not only queerer than we suppose, but queerer than we CAN suppose. I have read and heard many attempts at a systematic account of it, from materialism and theosophy to the Christian system and Kant, and I have always felt that they were much too simple. I suspect that there are more things in heaven and earth than are dreamed of, or can be dreamed of, in any philosophy. That is the reason why I have no philosophy myself, and must be my excuse for dreaming.”