This paper develops a phenomenological defense of Ian Hacking's experimental realism about unobservable entities in physical science, employing historically undervalued resources from the phenomenological tradition in order to clarify the warrant for our ontological commitments in science. Building upon the work of Husserl, Merleau-Ponty and Heelan, the paper provides a phenomenological correction of the positivistic conception of perceptual evidence maintained by antirealists such as van Fraassen, the experimental relevance of which is illustrated through a phenomenological interpretation of the 1974 discovery (...) of the J/ ψ particle generally regarded as evidence for the charmed quark. The argument then turns to address known problems in Hacking's account, demonstrating that his own instrumentalist criterion of the real is inadequately rooted in the phenomenology of perception, and as a result, passes over the true ontological significance of experimental phenomena. The paper maintains that the proper criterion, only indirectly related to instrumentality, is the distinctive style of the real encountered in perception: empirical pregnancy. With this notion and Merleau-Ponty's associated reversibility thesis, I show that the phenomenological tradition provides insights into the warrant for our realist commitments that have yet to be adequately acknowledged by philosophers of science. (shrink)