  What these various forms of logical analysis suggest, then, is that  what characterizes analysis in analytic philosophy is something far  richer than the mere ‘decomposition’ of a concept into  its ‘constituents’. But this is not to say that the  decompositional conception of analysis plays no role at all. It can  be found in the early work of Moore, for example (see the  supplementary section on   Moore).  It might also be seen as reflected in the approach to the analysis of concepts that seeks to specify the necessary and sufficient  conditions for their correct employment. Conceptual analysis in this  sense goes back to the Socrates of Plato's early dialogues (see the supplementary section on   Plato).  But it arguably reached its heyday in the 1950s and 1960s. As  mentioned in   Section 2  above, the definition of ‘knowledge’ as ‘justified  true belief’ is perhaps the most famous example; and this  definition was criticised in Gettier's classic paper of 1963.  (For details of this, see the entry in this Encyclopedia on   The Analysis of Knowledge.)  The specification of necessary and sufficient conditions may no  longer be seen as the primary aim of conceptual analysis, especially  in the case of philosophical concepts such as  ‘knowledge’, which are fiercely contested; but  consideration of such conditions remains a useful tool in the  analytic philosopher's toolbag.