  Buridan’s treatment of proper names depends on his insistence that a singular term must be subordinated to a singular concept, and that the formation of a singular concept depends on the actual presence of the singular thing. No one can hand on a singular concept to another by definition or explanation. In his Questiones in Metaphysicam, Buridan considered the names ‘Antichrist’ and ‘Aristotle’. He argued that ‘Antichrist’, the favorite example of a name referring to a person who does not yet exist, is not a singular term, since it is formed from ‘anti’ and ‘Christ’, and could apply to many individuals. He then turned to his own favourite example, ‘Aristotle’.  If I am in the presence of Aristotle, and I dub him ‘Aristotle’, then the name is a genuinely singular term. But if Aristotle is a figure in the distant past, then my concept of Aristotle must be a descriptive one, containing such general elements as ‘man’, ‘great philosopher’, ‘born in Greece’, and so on. Given that there was indeed such a man, having just those characteristics, then my concept supposits for Aristotle, and so stability of reference is guaranteed, but since the concept is not and cannot be a singular concept, it seems that ‘Aristotle’ cannot be a proper singular term when uttered by me, but only an individual by circumlocution. 