ABSTRACT
During the twentieth century, logic underwent a fundamental rebirth. It introduced and embraced various kinds of artificial languages. The employment of these languages looked to be extremely helpful and as though it might elevate logic to a brand new level of rigor and clarity. The liberation of logic from the yoke of psychology, combined with its fruitful alliance with mathematics, provided for the explosion of results that we know from the twentieth century. However, the change that logic underwent in this way was in no way trivial, and it is also far from trivial to determine the extent to which the “new logic” only engaged new and more powerful instruments to answer the questions posed by the “old” one, and the extent to which it replaced the questions with new ones. And insofar as a replacement took place, it is not easy to see whether it was because the old questions were found to be ill-conceived or obsolete, or whether what was going on was that the shift in the questions being asked was not really noticed and that logic had moved somewhere without its protagonists duly reflecting on it. An optimistic picture is that nothing significant happened in this regard, that logic only sharpened its tools and delimited its subject matter with greater precision. This chapter, however, questions such optimism.
