  In this contributed presentation, we discuss and compare the mutually
opposite procedures of deformations and contractions of Lie algebras. We
suggest that with appropriate combinations of both procedures one may construct
new Lie algebras. We first discuss low-dimensional Lie algebras and illustrate
thereby that whereas for every contraction there exists a reverse deformation,
the converse is not true in general. Also we note that some Lie algebras
belonging to parameterized families are singled out by the irreversibility of
deformations and contractions. After reminding that global deformations of the
Witt, Virasoro, and affine Kac-Moody algebras allow one to retrieve Lie
algebras of Krichever-Novikov type, we contract the latter to find new infinite
dimensional Lie algebras.
