xv, 256 p. : ill. / This dissertation stages a reciprocal critique between traditional and marginal philosophical approaches to language on the one hand and interdisciplinary studies of speech-accompanying hand gestures on the other. Gesturing with the hands while speaking is a ubiquitous, cross-cultural human practice. Yet this practice is complex, varied, conventional, nonconventional, and above all under-theorized. In light of the theoretical and empirical treatments of language and gesture that I engage in, I argue that the hand gestures that spontaneously accompany speech are a part of language; more specifically, they are enactments of linguistic meaning. They are simultaneously (acts of) cognition and communication. Human communication and cognition are what they are in part because of this practice of gesturing. This argument has profound implications for philosophy, for gesture studies, and for interdisciplinary work to come. As further, strong proof of the pervasively embodied way that humans make meaning in language, reflection on gestural phenomena calls for a complete re-orientation in traditional analytic philosophy of language. Yet philosophical awareness of intersubjectivity and normativity as conditions of meaning achievement is well-deployed in elaborating and refining the minimal theoretical apparatus of present-day gesture studies. Triangulating between the most social, communicative philosophies of meaning and the most nuanced, reflective treatments of co-speech hand gesture, I articulate a new construal of language as embodied, world-embedded, intersubjectively normative, dynamic, multi-modal enacting of appropriative disclosure. Spontaneous co-speech gestures, while being indeed spontaneous, are nonetheless informed in various ways by conventions that they appropriate and deploy. Through this appropriation and deployment speakers enact, rather than represent, meaning, and they do so in various linguistic modalities. Seen thusly, gestures provide philosophers with a unique new perspective on the paradoxical determined-yet-free nature of all human meaning. / Committee in charge: Mark Johnson, Chairperson; Ted Toadvine, Member; Naomi Zack, Member; Eric Pederson, Outside Member