The family Formicidae is redefined on the basis of all common characters shared by its members, which allows a hypothetical sketch of its unknown presumed ancestor. The first cladistic analysis is presented of internal ant phylogeny at the subfamily level, based on the 10 extant subfamilies commonly recognized in the literature. Although some weaknesses remain, this phylogenetic reconstruction shows several concrete improvements. None of the fossil subfamilies allow comparison with the recent subfamilies by neontological criteria. Among recent subfamilies no autapomorphic characters have been found for the Aneuretinae which clearly show only primitive character states easy to identify by comparison with the Dolichoderinae. The former subfamily has been regarded as a straightforward synonym of the latter. The Ponerinae have been still characterized tentatively on the basis of two weak synapomorphies but the real monophyly of its members appears to be questionable. The subfamilial phylogeny, as a whole, appears relatively weakly documented on several branchings with exception of the Nothomyrmeciinae, Dolichoderinae, and Formicinae on one side which can be easily opposed to all remainder recent subfamilies on the other side, by having a constriction after abdominal segments I and II only instead of after segments I, II, and III. Another important conclusion reached in this paper concerns the Formicinae, which can no longer be considered as the most advanced extant ants.