l. The work of Ludwig Boltzmann (1844-1906) consists of two kinds of writings: in the first part of his active life he devoted himself entirely to problems of physics, while in the second part he tried to find a philosoph 1 ical background for his activities in and around the natural sciences. Most scientists are much more aware of his creative work in physics than of his digressions on the meaning and structure of science. I think in the present case the reason is not so much that most scientists are usually almost entirely occupied with their trade, because Boltzmann's philosophical work is also concerned with the (natural) sciences. I rather believe that the quality and consistency of Boltzmann's purely scientific work is of a more appealing nature than his less structured considerations on human activity in science and in life in general. 2. I think that it may be appropriate for the readers of this anthology to say a few words on the main findings of Boltzmann in physics, since in the end their 'philosophical' inlpact has been larger than the effect of his later writings. Moreover some knowledge of his scientific achievements can be helpful for the understanding and appreciation of the essays printed in this book, which almost all stem from Boltzmann's philosophical period. Boltzmann was one of the main protagonists - at least in continental Europe - of atomistics for explaining the phenomena of physics.

Inhalt
I/From Populäre Schriften: (Writings addressed to the Public).- Dedication (1905).- Foreword (1905).- 1. On the Methods of Theoretical Physics (1892).- 3. The Second Law of Thermodynamics (1886).- 5. On the Significance of Theories (1890).- 9. On Energetics (1896).- 10. On the Indispensability of Atomism in Natural Science (1897).- 11. More on Atomism (1897).- 12. On the Question of the Objective Existence of Processes in Inanimate Nature (1897).- 14. On the Development of the Methods of Theoretical Physics in Recent Times (1899).- 16. On the Fundamental Principles and Equations of Mechanics, I, II (1899).- 17. On the Principles of Mechanics, I, II (1900, 1902).- 18. An Inaugural Lecture on Natural Philosophy (1903).- 19. On Statistical Mechanics (1904).- 20. Reply to a Lecture on Happiness given by Prof. Ostwald (1904).- 22. On a Thesis of Schopenhauer's (1905).- II/From Nature51 (1895).- On Certain Questions of the Theory of Gases.- III/From Encyclopaedia Britannica10,11.- Model (1902).- IV/From Vorlesungen Über Die Principe Der Mechanik (Lectures on the Principles of Mechanics).- One (1897).- Two (1904).- Index Of Names.