chapter that contains an original discovery in theoretical physics, which is largely unheard of in books that are usually categorized as "gender studies" or "cultural theory" books. In this book, Barad also argues that "agential realism," is useful to the analysis of literature, social inequalities, and many other things. This claim is based on the fact that Barad's agential realism is a way of understanding the politics, ethics, and agencies of any act of observation, and indeed any kind of knowledge practice. According to Barad, the deeply connected way that each "thing" is entangled with everything else in materially specific ways means that all intra-actions reconfigure the entanglements. Barad's innovative and far-reaching formulation of intra-action, which challenges the usual notion of interaction which assumes a metaphysics of individualism, offers a new formulation of causality. There are not things that interact but rather through and within intra-actions there is a differentiating-entangling so that an agential cut is enacted that cuts things together-apart (one move) such that differences exist not as absolute separations but in their inseparability (i.e., "agential separability" as Barad calls it). Nothing is inherently separate from anything else, but separations are enacted within phenomena. This view of knowledge provides a framework for thinking about how culture and habits of thought can make some things visible and other things easier to ignore or to never see. For this reason, according to Barad, agential realism is useful for feminist analysis and other forms of political and social thought, even if the connection to science is not apparent. Barad's framework makes several other arguments, and some of them are part of larger trends in fields such as science studies and feminist technoscience (all can be found in their 2007 book, Meeting the Universe Halfway): They define agency as a relationship and not as something that one "has." The scientist and the social are always part of the apparatus, and one needs to take account of this in its inseparability in analyzing the system. This differs from the view that political critiques of science seek to undermine the credibility of science; instead, Barad argues that this kind of critique actually makes for better, more credible science. They argue that politics and ethical issues are always part of scientific work, and only are made to seem separate by specific historical circumstances that encourage people to fail to see those connections. One example they discuss