  Further issues to do with proper names arose from Buridan’s discussion of identity through time in the last redaction of his commentary on Aristotle’s Physics where he posed the question “Is Socrates the same today that he was yesterday?” In his answer, Buridan makes a careful distinction between three kinds of numerical identity through time. In the strictest sense, being totally the same in number, no change of any kind is allowed, and so there are very few real individuals, perhaps only God. In the less strict sense, being partially the same in number, the continuity of one part is sufficient. Socrates is the same Socrates despite bodily changes, because he has the same soul, but the human body will not retain its identity through time, and neither will a horse. In the least strict sense of identity, being the same according to the continuity of diverse parts succeeding one another, we find that animals, bodies, and rivers can be regarded as minimally the same through time. The Seine is the same river now as it was ten years ago because of the continuous succession of water-parts. This allows us to use the word ‘Seine’ as if it were a singular term in accordance with the customary modes of speech.  It is important to note that we are allowed to retain singular concepts through memory, so I can keep the same concept through time provided I have had the requisite original experience of the individual in question.