[89] The various observations which I propose to make here take as their point of departure a simple enough assertion, this being that for the Muslim historian the caliph only exists in practical terms from the moment that he is seen as the guide of the State, as the imām reorienting history. It is true that then - however insignificant his reign may be - he becomes the fulcrum around which all events gravitate. But for the purposes of knowing more about the infancy and education of the heir to the throne - an essential tool for the appreciation of the true worth of his future style of government - the written materials at our disposal are sporadic and not particularly fruitful, and furthermore are supplied to us only in cases of direct overlapping with the reign of the predecessor (since it is only under this heading that the chronicler judges them worthy of transmission to posterity). It may be recalled briefly that education is a phenomenon with diverse aspects - anthropological, ethical, genetic, sociological, etc. - not confined, in different languages, to a single exclusive notion. In German the concepts of Erziehung and Bildung are treated separately; in Russian there is an even more rigorous distinction between vospitaniye and obrazovaniye; similarly, in French, there is a distinction between éducation and culture, formation, while the English language encompasses both notions with the term “education”. [90] In the survey which follows, “education” is taken to mean everything which models the character of the child-pupil, everything that conveys to him, by way of apprenticeship, theoretical discernment and practical knowledge.