Testimonial worth

This paper introduces and argues for the hypothesis that judgments of testimonial worth are central to our practice of normatively appraising speech. It is argued that judgments of testimonial worth are central both to the judgement that an agent has lied, and to the acceptance of testimony. The hypothesis that, in lying, an agent necessarily displays poor testimonial worth, is shown to resolve a new puzzle about lying, and the recalcitrant problem raised by the existence of bald faced lies, and selfless assertions. It is then shown that the notion of testimonial worth allows us to capture the distinction between taking a speaker at their word, and treating them as a mere indicator of the truth in a way other theories fail to do

A Sum-of-Squares Approach to the Analysis of Zeno Stability in Polynomial Hybrid Systems

Hybrid dynamical systems can exhibit many unique phenomena, such as Zeno behavior. Zeno behavior is the occurrence of infinite discrete transitions in finite time. Zeno behavior has been likened to a form of finite-time asymptotic stability, and corresponding Lyapunov theorems have been developed. In this paper, we propose a method to construct Lyapunov functions to prove Zeno stability of compact sets in cyclic hybrid systems with parametric uncertainties in the vector fields, domains and guard sets, and reset maps utilizing sum-of-squares programming. This technique can easily be applied to cyclic hybrid systems without parametric uncertainties as well. Examples illustrating the use of the proposed technique are also provided

Lost in transmission: Testimonial justification and practical reason

Transmission views of testimony hold that a speaker's knowledge or justification can become the audience's knowledge or justification. We argue that transmission views are incompatible with the hypothesis that one's epistemic state, together with one's practical circumstances, determines what actions are rationally permissible for an agent. We argue that there are cases where, if the speaker's epistemic state were transmitted to the audience, then the audience would be warranted in acting in particular ways. Yet, the audience in these cases is not so warranted, as their strength of justification does not come close to the speaker's