Abstract
The present situation in our understanding of high-energy physics is reviewed. In high-energy physics we have a plethora of theories, which often look quite incompatible, but which share one grand claim. For each of them it has been possible to find at least one set of experimental data with which they agree. We summarize the outstanding experimental features which are discernible in the nucleon-nucleon system at energies above about 3-GeV/c laboratory momentum. We consider some of the main theoretical ideas and examine to what extent they are compatible with the experimental properties described.