This book is a collection of articles by Hempel since the early 1930s, some of which were previously untranslated or were difficult to find. The books begins with the "carnapian Hempel" (a phase with many phases) and ends with the "kuhnian Hempel". Hempel is lucid and patient, although his observations are sometimes a bit superficial, especially when he frames his mind in 1st order logic and fears to go anywhere beyond.
I particularly liked the article on the content of probability statements.
It is a pity that his paper on "Geometry and empirical science" was not included.

A very insightful and comprehensive collection of writings by the german philosopher C.G.Hempel, an author that belongs to the same league of masters like Carnap and Reichenbach , and whose visions on matters like the scientific value of inductive inferences are positively outstanding and revolutionary.