The Logic of Scientific Discovery is a translation of Logik der Forschung, published in Vienna in the autumn of 1934 (with the imprint ' 1935'). The translation was prepared by the author, with the assistance of Dr. Julius Freed and Lan Freed.
The original text of 1934 has been left unchanged for the purpose of the translation. As usual, the translation is a little longer than the original. Words and phrases for which no equivalent exists had to be paraphrased. Sentences had to be broken up and rearranged--the more so as the text to be translated was highly condensed: it had been several times drastically cut, to comply with the publisher's requirements. Yet the author decided against augmenting the text, and also against restoring cut passages.
In order to bring the book up to date, the author has added new appendices and new footnotes. Some of these merely expand the text, or correct it; but others explain where the author has changed his mind, or how he would now reframe his arguments.
All new additions--new appendices and new footnotes--are marked by starred numbers; and where old footnotes have been expanded, the expansion is also marked by a star (unless it consists only of a reference to the English edition of a book originally quoted from a German edition).
In these new starred additions, references will be found to a sequel to this volume, entitled Postscript: After Twenty Years (not previously published). Its chapters and sections are also preceded by starred numbers. (Since it has no appendices, all references to appendices, whether starred or not, refer to the present volume.) The two volumes treat of the same problems. Though they complement each other, they are independent.
It should also be mentioned that the numbering of the chapters of the present volume has been changed. In the original, they were numbered i to ii (part i), and i to viii (part ii). They are now numbered through from i to x.