The role of the quark condensate for the low energy structure of QCD is
discussed in some detail. In particular, the dependence of M_pi on m_u and m_d
and the low energy theorems for the pi-pi scattering amplitude are reviewed.
The new data on Ke4 decay beautifully confirm the standard picture, according
to which the quark condensate is the leading order parameter of the
spontaneously broken chiral symmetry.Comment: Talk given at the Workshop QCD@Work, Martina Franca, June 200