I am aware that my use of certain new terms has proved a stumbling stone to many; it was bound to be so. I deliber ately adhere to my view, however, that for new distinctions, and for Old ones too that have no proper names, unambiguous terms are absolutely requisite. In this matter I enrol myself under the banner of the American apostle of clear terminology in this field, C. S. Peirce. If any of the views expressed in my work survive, the terms will win out too; if the views do not survive, the terms may perish with them A word on this point and also on other criticisms will be found in the Appendix to this volume and certain of the points made there, especially the remarks on meaning and on assumption, may be referred to as supplementary to topics of Vol. I. The intima tions in the matter of the aesthetic, also in the Appendix, anticipate conclusions reached in Volume III. An error was made in the Preface to Vol. I., in the statement that the third volume was to appear in a year. It was this volume, the second, that was intended. The third volume is writing, but not written.