  The aim of this introductory lecture is to review the arguments, according to
which the symmetry properties of the strong interaction reveal themselves at
low energies. I first discuss the symmetries of QCD, then sketch the method
used to work out their implications and finally take up a few specific issues,
where new experimental results are of particular interest to test the
predictions. (Talk given at the Workshop "Chiral Dynamics: Theory and
Experiment", July 1994, MIT, BUTP 94/18)
