 A second difficulty facing inference to the best explanation concerns the pools of theories regarding which judgments of relative explanatory efficacy are made. Even if scientists are likely reliable rankers of theories with respect to truth, this will not lead to belief in a true theory (in some domain) unless that theory in particular happens to be among those considered. Otherwise, as van Fraassen (1989: 143) notes, one may simply end up with “the best of a bad lot”. Given the widespread view, even among realists, that many and perhaps most of our best theories are false, strictly speaking, this concern may seem especially pressing. However, in just the way that the realist strategy of selectivity (see  section 2.3)  may offer responses to the question of what it could mean for a theory to be close to the truth without being true simpliciter, this same strategy may offer the beginnings of a response here. That is to say, the best theory of a bad lot may nonetheless describe unobservable aspects of the world in such a way as to meet the standards of variants of realism including explanationism, entity realism, and structural realism. (For a book-length treatment of inference to the best explanation, see Lipton [1991] 2004; for defenses, see Lipton 1993; Day &amp; Kincaid 1994; and Psillos 1996, 2009: part III; for critiques, see van Fraassen 1989: chs. 6–7; Ladyman, Douven, Horsten, &amp; van Fraassen 1997; Wray 2008; and Khalifa 2010.)