This article discusses three recent philosophers who speak in different ways about the retroactive construction of reality by human knowledge. Bruno Latour unapologetically claims that the Egyptian Pharaoh Ramses II could not have died of tuberculosis, as determined by a team of French doctors in 1976, since this disease was not discovered until three thousand years after his death. Slavoj Žižek often makes comparable arguments, though his version of retroactivity draws on both psychoanalysis and dialectics in a way that is (...) never the case for Latour. Yet in his 2012 book Less Than Nothing, Žižek takes the more prudent, realist-sounding line that changes in scientific theories do not change nature itself. The real novelty in retroactive theories is provided by Thomas Kuhn, who draws our attention to a grey temporal zone in scientific discovery in which it is impossible to pinpoint the exact date of any breakthrough. For Kuhn, this stems from a dualism found in reality itself: one between the fact “that” a thing exists and the determination of “what” its properties are. The tension between these two moments is responsible for much of the vagueness and drama surrounding any paradigm shift in the sciences and is closely related to at least one plausible theory of metaphor. In closing, three Hollywood films are cited as helpful examples for understanding the different ways in which a paradigm shift works its retroactive magic. (shrink)