Recently, the chiral logarithms predicted by quenched chiral perturbation
theory have been extracted from lattice calculations of hadron masses. We argue
that the deviations of lattice results from random matrix theory starting
around the so-called Thouless energy can be understood in terms of chiral
perturbation theory as well. Comparison of lattice data with chiral
perturbation theory formulae allows us to compute the pion decay constant. We
present results from a calculation for quenched SU(2) with Kogut-Susskind
fermions at \beta=2.0 and 2.2.Comment: LaTeX, 12 pages, 7 .eps figure
