 Because of the peculiar nature of black holes as physical systems, the attempt to observe them also raises interesting epistemic problems about, inter alia, under-determination of theoretical models by data, the way that theoretical assumptions play ineliminable roles in the interpretation of data, and what it means at all to “observe” a physical system that is, in principle, able to emit no signal directly. Eckart et al. (2017) provides a comprehensive survey of the issues; see also Collmar et al. (1998) for the record of a round-table discussion on these questions by a group of eminent theoreticians and observational astronomers. In light of the recent epoch-making detection by LIGO of gravitational waves with a signature indicating they were generated by a binary black-hole system coalescing (Abbott et al. 2016), these issues become even more urgent for philosophers to explore. 