The semantics of dasein and the modality of Being and Time

Being and Time is a methodologically complex work, combining hermeneutic, transcendental, phenomenological, and ontological strategies in a provocative and not-obviously-stable concoction. In this article, I focus on one strand of the methodological puzzles raised by Heidegger’s undertaking: the problem of warranting the modal claims that occur frequently in the course of Heidegger’s project. In a number of crucial passages, we are told that one or another trait of Dasein is necessary, or that some ontic feature of Dasein would not be possible were it not for some deeper ontological feature. I undertake to determine the logical form of these doctrines, and to consider what kind of evidence might suffice to establish them. I draw on Heidegger’s complex debt to Dilthey in proposing an interpretation of the notion of an existeniale, and I critically assess Taylor Carman’s treatment of Heidegger’s project as an extension of Kantian transcendental strategies. In the end, I argue, much comes to turn on one’s account of the semantics of Heidegger’s central term of art: “Dasein.” I identify shortcomings in two possible approaches to this problem: one takes the extension of the term to be antecedently fixed; the other fixes the meaning of the term by specifying its intension. I then explore an alternative semantics for “Dasein” under which the modalized doctrines of Being and Time can be considered de re necessities. All three of the semantic models that I consider here remain highly schematic – cartoons rather than fully elaborated portraits – and I do not mean to suggest that any of the three would suffice to capture the enormously complex semantic structure of Heidegger’s undertaking. Nonetheless, I argue that the third semantic model enjoys certain demonstrable advantages over the other two, both for mounting a defense of Heidegger’s modal propositions and as a schema for mapping the text of Being and Time. It also allows us to frame a challenge that any fully adequate semantic interpretation of Heidegger’s text would have to meet.