Much of twentieth-century philosophy was organized around the "linguistic turn," in which metaphysical and epistemological issues were approached through an analysis of language. This turn was marked by two assumptions: that it was primarily the semantics of language that was relevant to broader philosophical issues, and that declarative assertions were the only verbal acts of serious philosophical interest. In 'Yo!' and 'Lo!' Rebecca Kukla and Mark Lance reject these assumptions. Looking at philosophical problems starting with the pragmatics of language, they develop a typology of pragmatic categories of speech within which declaratives have no uniquely privileged position. They demonstrate that non-declarative speech acts--including vocative hails ("Yo!") and calls to shared attention ("Lo!")--are as fundamental to the possibility and structure of meaningful language as are declaratives.
Entering into conversation with the work of Anglo-American philosophers such as Wilfrid Sellars, Robert Brandom, and John McDowell, and Continental philosophers including Heidegger and Althusser, 'Yo!' and 'Lo!' offers solutions (or dissolutions) to long-standing philosophical problems, such as how perception can be both inferentially fecund and responsive to an empirical world, and how moral judgment can be both objective and inherently motivating.
This is a phenomenal work of philosophy that primarily focuses on language, but makes interesting predictions and comments in ethics, mind, and even a bit of social development at the end. It is definitely not written for people brand new to philosophy, as the authors consistently reference numerous other big names in the field, like Brandom and Sellars. A close reader could probably pick up on their theories using context clues, but it would certainly be easier if they were already up-to-speed. Aside from the content itself, this is not a difficult read at all. The writing is clear, and there are lots of good examples that really drive in every point.
This gives a very thorough pragmatic approach to language, focusing on how speech acts functionally convert inputs like entitlements to outputs like commitments. A lot of the book is honestly anticlimactic in the best way, since every conclusion they arrive at concerning that pragmatic topography seems so obvious after reasoning through the premises.
The only criticism I have is that the authors never mention questions, despite them playing a very unique role in language. The authors spend a majority of the book describing what they believe are the most fundamental speech acts and how the less fundamental speech acts relate to them, but never talk about how questions work in with declaratives or imperatives.