It seems still to be necessary to insist that it is not reasonable to assume as an indisputable fact that man can arrive at an "explanation" of existence and the nature of things. This assumption has been made in the past, and, by a well-known trick of advocacy, it has been argued that since science fails to "explain" these things, the old prehistoric fancies as to spirits--even though they "explain" nothing and have themselves to be "explained"--hold the field and must be accepted as true. There is an alternative, and that is to admit our ignorance. No man has ever seen or knows what is on the other side of the moon, that which does not face our earth. There are few amongst us who, in this admitted and complete state of ignorance, would persist in declaring that we must accept as true the suppositions of ancient races of men as to the existence there of men-like creatures, or would be deluded by the argument that since we do not know what is there the suppositions in question must be accepted as true. We cannot, as a matter of observation, assert that these supposed beings are not there, but we can find no reason to make it appear even probable, nor any means of proving by experiment, that they are. We refuse to entertain such suppositions. FOOTNOTES: [Footnote 10: This subject is discussed and some account of the chemical nature of protoplasm given in my book, "Science from an Easy Chair" (Methuen, 1910), which consists of a first series of papers similar to those which are collected in the present volume as a "Second Series." The chapters in the earlier volume to which I wish to direct the reader's attention are those entitled "The Universal Structure of Living Things," "Protoplasm, Life and Death," "Chemistry and Protoplasm," "The Simplest Living Things."] _Printed in Great Britain by_ UNWIN BROTHERS, LIMITED WOKING AND LONDON A FEW OF Messrs. Methuen's PUBLICATIONS Abraham (George D.). ON ALPINE HEIGHTS AND BRITISH CRAGS. Illustrated. Demy 8vo, 10s. 6d. net. Atkinson (T. D.). ENGLISH ARCHITECTURE. Illustrated. _Fifth Edition._ Fcap. 8vo, 6s. net. Baggally (W. Wortley). TELEPATHY, GENUINE AND FRAUDULENT. Crown 8vo, 3s. 6d. net. Bain (F. W.).-- In the Great God's Hair (_Seventh Edition_); A Draught of the Blue (_Seventh Edition_); An Incarnation of the Snow (_Fourth Edition_); A Mine of Faults (_Fifth Edition_); A Digit of the Moon (_Thirteenth Edition_); The Livery of Eve (_Second Edition_); A Heifer of the Dawn (_Tenth Edition_); An Essence of the Dusk (_Fourth Edition_); The Descent of the Sun (_Eighth Edition_); The Ashes of a God (_Third Edition_); Bubbles of the Foam (_Third Edition_); A Syrup of the Bees (_Second Edition_); The Substance of a Dream (_Second Edition_). Fcap. 8vo, 5s. net each. Baring-Gould (S.). THE TRAGEDY OF THE CAESARS: A Study of the Characters of the Caesars of the Julian and Claudian Houses. Illustrated. _Seventh Ed._ Royal 8vo, 15s. net.