Benatar’s Asymmetry Argument has been challenged in a number of places. Some have suggested that the distinction between a life worth starting and a life worth continuing does not hold up to scrutiny (DeGrazia 2012; Metz 2011, 241). Why think these are two distinct standards? For example, why not hold that a life worth starting just is a life that will be worth continuing? Some have argued that Benatar does not do enough to defend this distinction, which is an important one for the success of his argument. Another objection has been to challenge directly the asymmetries defended by Benatar. While Benatar suggests that an absence of pleasure is not bad unless there is an individual who is deprived of it, perhaps it is better understood as not good (Metz 2011, 242). Likewise, maybe an absence of pain is better understood as not bad (Metz 2011, 242-243). This would modify Benatar’s chart to the following:

There are at least two reasons to favour this symmetry to the asymmetry posited by Benatar. First “is the fact of symmetry itself. As many physicists, mathematicians and philosophers of science have pointed out, symmetrical principles and explanations are to be preferred, ceteris paribus, to asymmetrical ones” (Metz 2011, 245). Second, the symmetry may better explain “uncontroversial judgments about the relationship between experiences such as pleasure and pain and their degree of dis/value” (Metz 2011, 245).

Another alternative understanding of the four procreative asymmetries Benatar claims are best explained by the basic asymmetry between pain and pleasure is the idea that the four asymmetries themselves are fundamental. As such they need not rely on a further asymmetry for their explanation (2002, 354-355). For those who disagree, DeGrazia writes that another alternative explanation is that “we have much stronger duties not to harm than to benefit and that this difference makes all the difference when we add the value of reproductive liberty. If so, the asymmetry about procreative duties does not favor the fundamental asymmetry between benefit and harm championed by Benatar” (DeGrazia 2010 322).

Ben Bradley argues that Benatar’s asymmetry fails because “there is a conceptual link between goodness and betterness; but if pleasure were intrinsically good but not better than its absence, there would be no such link” (Bradley 2013, 39; see also Bradley 2010).
Elizabeth Harman claims that Benatar’s Asymmetry Argument “equivocates between impersonal goodness and goodness for a person” (2009, 780). It is true that the presence of pain is bad. It is both personally and impersonally bad. However, the absence of pain is only impersonally good since there is no person who exists to experience its absence (Harman 2009, 780). But for the asymmetry to hold Benatar would have to show that absence of pain is also personally good. All of the various rejoinders to these claims cannot be discussed, but it is noteworthy that Benatar has directly responded to many criticisms of his arguments (for example, Benatar 2013).