This essay enjoins Lacanian psychoanalysis to address a recurrent question in the philosophy of science regarding the role of gender (or perhaps other social categories) in the production of objective knowledge. Are social categories “merely empirical” and thus mitigated by the formal procedures of scientific investigation or is gender somehow implicated in the constitution of knowledge itself? Evelyn Fox Keller, in her monumentally influential work on gender and science, makes the case for a constitutive effect. This essay, using data from a year-long study of science labs and the concepts of Lacan, attempts to further Fox Keller's project by substituting object relations and the categories one thus has at one's disposal with an understanding of the structural effects of language (as limitation and the introduction of difference) as these are graphed on to embodied being, giving forms of what culture reveres as sexual difference - the phallic one vs the Other. Implications for thinking gender in science are suggested and those for the daily operations of research labs are also noted.