Modern formal logic is a curious beast: while it does not abound in comprehensive and detailed historical works, it went through so many changes (both regarding terminology and content) that it deserves even philologically deep inquiries. Choosing the topic and issue of discussion is, however, a delicate matter. One either decides for a classic text that influenced generations of scholars, was translated into various languages and set the stage for further research; or one deals with such smaller fishes that filled the ocean and provided such ideas and material that could have been taken up by big fishes. While usually the policy making big ones cannot exist without the smaller ones, in the history of philosophy and especially in the history of logic it is a quite convenient strategy to start with the big fishes.