  We argue that a convenient way to analyze instabilities of black holes in AdS
space is via Bragg-Williams construction of a free energy function. Starting
with a pedagogical review of this construction in condensed matter systems and
also its implementation to Hawking-Page transition, we study instabilities
associated with hairy black holes and also with the $R$-charged black holes.
For the hairy black holes, an analysis of thermal quench is presented.
