Chiral symmetry on the lattice
  As a non-perturbative and gauge invariant regularization the lattice provides a tool for deeper understanding of the celebrated Yang-Mills theory, QCD and chiral gauge theories. For illustration, I discuss some analytic developments on the lattice related to chiral symmetry, chiral fermions and improvement programs. Chiral symmetry on the lattice has an amazing history, and it might influence our perception of a symmetry beyond this example. 
Peter Hasenfratz