1 6 4 D O C U M E N T 1 8 7 M A Y 1 9 2 2 been here exactly 14 days.[3] Tomorrow we’ll be seeing Lorentz.[4] I was not able to teach a course but did manage to get some other things done. Warm regards to all of you from your Albert. 187. From Edward H. Synge Knockroe, Dundrum, Co. Dublin Ireland. 10. V. 22 Dear Dr Einstein, I wish to thank you for your kindness in sending me an appreciation of Hamil- ton’s work.[1] I am sure it will be very useful to us in getting people to take an in- terest in the project. When you mentioned that the genesis of Hamilton’s ideas was hard to under- stand it occurred to me that it might interest you to know, what appears clear from Graves’ Life of Hamilton,[2] that a philosophic viewpoint which is very unusual among scientists seems to have been responsible here. Hamilton was a Neo-Plato- nist, and one gathers that he expected to find in Nature the exemplification of laws which satisfied his sense of intellectual beauty. In fact he regarded such satisfaction of one’s intellect as the “raison d’être” of these laws, and went so far as to question whether the laws of Nature were not specially created to develope the intellects of men “and angels”!! However odd such a standpoint may seem, it appears to be a powerful agent on heuristic grounds, since it makes explicit an instinctive feeling which I believe is shared in by many mathematicians, that the most abstract re- searches will be found adequately exemplified somewhere in Nature. For instance it would lead one to look for some physical exemplification of Riemann’s surfaces, and from the way in which “quanta” occur here one might perhaps hope for some bridge between your quanta and gravitational theories in this direction. I am sanguine enough to believe that a great deal in the way of general view- points may still be derived from a first hand study of Hamilton’s work, and I espe- cially hope that mathematicians may realise that Hamilton’s system of quaternions was conceived by him as a Space Time symbolism, and that the possibilities of a general development of a theory of functions of quaternions (perhaps on a sheeted Space-Time) may be explored, with a view to finding physical exemplifications and seeing whether there may not be something in a guess which Hamilton has put on record “that a function of a quaternion might be the law of the universe.”