This paper reconsiders what implications quantum decoherence has for Karen Barad’s agential realism. In contrast with the recent claim of Thomas Everth and Laura Gurney (2022), this paper argues that decoherence supports rather than defeats the holist, relational ontology of agential realism. Indeed, decoherence offers an explanation for how a quantum system can remain entangled and superposed in principle while it nevertheless in practice appears classical to a local observer. Decoherence shows why the appearance of classicality is not an objection to the ontology being in reality that of agential realism, in accordance with Barad’s repeated insistence that we should not mistake principle for practice. Whether users of agential realism in social theory should be encouraged by this is another matter that this paper does not take a stance on. As an ontology, however, agential realism is vindicated.

本文重新考虑了量子退相干对 Karen Barad 的代理现实主义的影响。与 Thomas Everth 和 Laura Gurney (2022) 最近的主张相反，本文认为退相干支持而不是击败代理现实主义的整体关系本体论。事实上，退相干解释了一个量子系统如何在原则上保持纠缠和叠加，而实际上它在局部观察者看来是经典的。Decoherence 说明了为什么古典性的出现并不是反对本体论实际上是代理现实主义的本体论，这与巴拉德一再坚持的我们不应该将原则误认为实践相一致。这是否应该鼓励社会理论中代理现实主义的使用者是本文不采取立场的另一件事。