Unpublished opening lecture for the course on the theory of relativity
  in Argentina, 1925
  Honorable Rector, Honorable Professors, and Students of this University: In
these times of political and economic struggle and nationalistic fragmentation,
it is a particular joy for me to see people assembling here to give their
attention exclusively to the highest values that are common to us all. I am
glad to be in this blessed land before a small circle of people who are
interested in topics of science to speak on those issues that, in essence, are
the subject of my own meditations.. [abridged].
