Bobbio's theoretical defence of the distinction between Left and Right, for all its eloquence, may thus be more vulnerable than it appears. If we ask why this should be so, the answer surely lies in the difficulty of constructing an axiology of political values without coherent reference to the empirical social world. Bobbio often writes as if he could separate his ideal taxonomy from contemporary history, but of course he cannot. In practice he admits the political scenery of the present into his account selectively, for the purposes of his argument. But it is in that present that the deeper reasons and limits of his intervention lie.