This paper examines a sequence of investigations in parasitology, botany, pharmacology, psychometrics and ethnopsychology focused on Kenyan village children's knowledge of medicinal herbs. We follow this work of making and ordering of knowledge, showing that the different disciplinary perspectives on bodies, medicines, knowledges, children and cultures produced by this research all sought the foundation of knowledge in reference to objective reality, and that they aimed to make the world known in the specific form of distinct and comparable entities with individual properties and capacities. Based on subsequent ethnographic observations of healing in the same village, we outline a different, contrasting modality of knowing, which places ontology above epistemology. Medicinal knowledge and its transformational capacity are here not located within entities but between them; not in objective reality but in effects; 'to know' means 'to come together' with the implication of having an effect on one another. We use this ethnographic sketch of a different form of knowing as a foil against which to contrast the imaginary that had shaped our previous research. Beyond the stark contrast between herbal village healing and pharmacological laboratory analysis, we expand our argument by moving from natural science to social science, from studies of plants and substances to those of humans, minds and cultures; from laboratories to ethno-psychological tests, cultural models, and eventually econometrics. We suggest that by reiterating a particular scientific imaginary, remaking humans (and non-human beings) as known things, a specific notion of man and a related political economy of knowledge is naturalized. Looking back at our involvement with this sequence of research, we realize that, contrary to our intentions, our inclusion as 'social scientists' into a multidisciplinary scientific project may have exacerbated rather than mitigated its potentially problematic effects.