  I give an outline of my proposal to take the QCD functional determinant in
lattice simulations partially into account: The determinant is split into two
factors, the factor referring to a standard background in each topological
sector is kept exactly, the factor describing the effect of the smooth
deviation of the actual configuration from the reference background is replaced
by one. The issue of how to choose the reference configurations is discussed
and it is argued that ``topologically unquenched QCD'' is an interesting
starting point to study full QCD in lattice simulations as it gets the main
qualitative features right from the beginning.
