This chapter develops an ethnomethodologically-informed view regarding the sociality of objects, building upon Garfinkel’s various descriptions of object constitution. We examine a particular case of diagnostic reasoning produced in the course of carrying out a surgical procedure at a teaching hospital. Our interest is in the methods employed by the surgeons in resolving certain incongruities in the case as it presents itself. Through an occasioned process of inquiry, the case at hand comes to be seen in a new light. This revised clinical picture is the oriented object under consideration here and it is produced as a discovered matter. We describe it as an instructed object to emphasise that perception is a kind of action and can too be taught. For us, as for Garfinkel, instruction is a fundamental feature of how social order is created and shared understanding sustained. In the analysed example, the methods by which a new appreciation of the case is achieved are public and inspectable. Instructional settings are, in this way, ‘perspicuous sites’ for investigating how “a world of meant objects” is produced.