 Lewontin’s conditions have been criticized from many directions. For one thing, they make no mention of the populations in which selection occurs, and though the second set of conditions refers to species, all the members of a single species may not form a single population for the purposes of applying selection theory. Populations must be appropriately circumscribed for some of the key vocabulary of evolutionary theory (focused selection, drift) to be deployed in a non-arbitrary fashion (Millstein 2009). Lewontin’s formulations also make no mention of the struggle for existence, a seminal notion for Darwin (see discussion in Lennox &amp; Wilson 1994). The principles have also been subject to counterexamples. On the one hand, authors put forward cases of evolving populations that fail to meet Lewontin’s conditions. Earnshaw-White (2012) puts forward a population in which offspring do not inherit their parents’ traits, but whose members exhibit differential survival such that the population will evolve to a stable equilibrium. Equally, differential heritability may lead to evolutionary change without differential fitness (Earnshaw-White 2012; but see Bourrat 2015). Despite failing to meet Lewontin’s conditions, populations will evolve that feature variants that differ not in average offspring number, but only in generation time, such that one variant reproduces twice as fast as the other (Godfrey-Smith 2007: 495). On the other hand, authors put forward cases of systems that fail to evolve despite meeting Lewontin’s conditions. A system exhibiting stabilizing selection, such that it tends to evolve toward an equilibrium state where multiple variants remain within the population, may meet either set of Lewontin’s conditions despite failing to evolve (Godfrey-Smith 2007: 504). Counterexamples of these sorts depend upon the assumption that we can tell whether a system is undergoing selection without applying any set of criteria for doing so (see Jantzen 2019 for a discussion of how a Lewontin-style approach to whether a system undergoes selection is question-begging).