 In part 1 of this entry we will describe in very broad outline the main existing views about how to understand the ideas of modality and formality relevant to logical truth. (A more detailed treatment of these views is available in other entries mentioned below, and especially in the entries on the  analytic/synthetic distinction  and  logical constants.)  In part 2 we will describe, also in outline, a particular set of philosophical issues that arise when one considers the attempted mathematical characterizations of logical truth. The question of whether or in what sense these characterizations are correct is bound with the question of what is or should be our specific understanding of the ideas of modality and  formality.[2]