"Namier himself treated it as virtually an axiom about all political behaviour that the actors engage in it solely out of a desire to acquire and exercise political power. It follows that their professed principles, or rather their "party names and cant", as Namier characteristically preferred to put it in The Structure of Politics, form no guide at all to the "underlying realities" of politics. They are invoked merely to ensure that the "unconscious promptings" and "inscrutable components" of personal ambition and the quest for domination which actually drive men into politics are "invested ex post facto with the appearance of logic and rationality". It follows that all such "abstract ideals" must be mere epiphenomena, which play no independent role in determining any courses of political action, and which not only can but ought to be bypassed if we are to give realistic explanations of political behaviour. As Namier himself put it in his essay on "Human Nature in Politics", "what matters most is the underlying emotions, the music, to which ideas are a mere libretto, often of very inferior quality". And, as several recent commentators on his work have stressed, it was his express hope in studying eighteenth-century politics (and a large part of the attraction which the subject held for him) to be able to show that "considerations of principle or even of policy had only limited relevance" in this period, that "what mattered in politics" at this time "was not attachment to principle but the struggle for office", and in general that "political ideas" are "rarely in themselves the determinants of human action"."