  These introductory lecture notes describe recent results on novel Mott
insulating phases which are "descendents" of superconductors - obtained by
"quantum disordering". After a brief overview of quantum magnetism, attention
is focussed on the spin-liquid phase of the two-leg Hubbard ladder and the
"nodal liquid" - a descendent of the $d_{x^2-y^2}$ superconductor. These notes,
which will appear in a future Les Houches publication, are self-contained and
an effort has been made to keep them accessible.
