Key points are not available for this paper at this time.
This volume continues a newly developing custom, which is to be highly welcomed, of honouring great contemporary figures of science on their 70th or 75th birthday with a collection of papers contributed by their colleagues. J L Synge is perhaps best known for his work in relativity where in particular he is largely responsible, in the wake of Minkowski, for emphasizing the importance of geometrical characterization in the theory.
Ray d’Inverno (Wed,) studied this question.