 Recently, Manchak (2014a) proposed a condition spacetimes may satisfy, manifestly relevant to the issue of what characterizes singular behavior, which he calls ‘effective completeness’. The idea is to try to give what may be thought of as a quasi-local characterization of path  incompleteness.[2]  Manchak (2014a, p. 1071) describes the intended physical significance as follows: “If a space-time fails to be effectively complete, then there is a freely falling observer who never records some particular watch reading but who ‘could have’ in the sense that nothing in her vicinity precludes it.” This condition has the pleasant property of being logically intermediate between the condition of geodesic incompleteness for spacetime, on the one hand, generally conceded to be too strong to capture the general idea of singular behavior (because of examples such that of Geroch 1968c, discussed above), and, on the other hand, the condition of being extendible, generally conceded to be too weak, for effective completeness is implied by geodesic completeness and in turn implies inextendibility. While this new condition appears promising as a clear and useful characterization of singular structure (in the sense of path incompleteness), and does so in a way that avoids the problems of physical opacity plaguing the semi-official definition, it is too new and unexplored for definitive judgments to be made about it. One wants to know, among other things, whether it can be used to prove novel theorems with the same physical depth and reach as the standard singularity theorems (Penrose 1965, 1968; Hawking 1965, 1966a, 1966b, 1966c, 1966d; Geroch 1966, 1967, 1968b, 1970; Hawking and Penrose 1970), and whether it can shed real light on the philosophical issues discussed below in  section 2.  