Review
It is not, I believe, too much to say that all the vital problems of philosophy depend for their solution on the solution of the problem of what Space and Time are and more particularly how they are related to each other.
Samuel Alexander1
The problem of time has always baffled the human mind.
Hans Reichenbach2
The modern advances in thermodynamics, relativity, cosmology and information theory, instead of clarifying our insight into this basic notion (time), seem so far only to have added to the general confusion.
Max Black3
There will have to be some new development that is quite unexpected, that we cannot even make a guess about.
P. A. M. Dirac4