The concept of congruence in Euclidean geometry is not exactly the same as that in non-Euclidean geometry...."Congruent" means in Euclidean geometry the same as "determining parallelism," a meaning which it does not have in non-Euclidean geometry.


The Philosophy of Space and Time (1928, tr. 1957)

Hans Reichenbach Quotes

The concept of congruence in Euclidean geometry is not exactly the same as that in non-Euclidean geometry....Congruent means in Euclidean geometry...

The concept of congruence in Euclidean geometry is not exactly the same as that in non-Euclidean geometry....Congruent means in Euclidean geometry...

The concept of congruence in Euclidean geometry is not exactly the same as that in non-Euclidean geometry....Congruent means in Euclidean geometry...

The concept of congruence in Euclidean geometry is not exactly the same as that in non-Euclidean geometry....Congruent means in Euclidean geometry...