Anglo-American general jurisprudence remains preoccupied with the relationship of
legality to morality. This has especially been so in the re-reading of Lon Fuller’s theory of an implied morality in any law. More often than not, Fuller has been said to
distinguish between the identity of a discrete rule and something called ‘morality’. In
this reading of Fuller, however, insufficient attention to what is signified by ‘morality’.
Such an implied morality has been understood in terms of deontological duties, the
Good life, naturalism, and subjectively posited values. Each of these interpretations
has a shared common denominator: namely, the distinction between ‘is’ and ‘ought’,
‘facts’ and ‘values’. Legality is said to be nested in an ‘is’ world. An ‘is’ cannot be derived from an ‘ought’. This essay aims to press this distinction further. Fuller, I intend to argue, does indeed accept the is/ought distinction as have his commentators. The associations of the ‘oughts’ with deontological duties, the Good life, naturalism and subjective values, however, have been misdirected. This has been so because Fuller presupposed that legality was a matter of a spatial structure. Non-law was situated outside the structure. If a legislator or judge considered matters outside the structure as if they were binding upon jurists and, for that matter, upon members of the legal structure, the law was not binding. The crucial incident of the structure was the boundary of the structure. Fuller’s structuralist theory of law offers the opportunity to better understand what he signified by ‘the internal morality of law’. I shall privilege several elements of his theory: the relation of legal units to a structure, the nature of a structure, the constituents of a structure (territorial space, its pillars and its matter); the forms of the legal structure; the centrifugal and centripetal structures, the structure and traditional theories of morality, the role of the legal official in a structure, and why the internal knowledge in the structure is binding. Fuller especially privileged two features of a legal structure. The one was the boundary of the structure. The second concerned the exteriority of the boundary. Both features presupposed a territorial sense view of legal knowledge. The legal mind analysed any social problem through the map of such a sense of legal space. By concentrating upon the discrete rule in isolation of the implied structural boundary to which the rule referred, commentators have attributed been misdirected in their analyses of Fuller’s theory of law and morality. My argument in this respect will proceed as follows. In order to clarify Fuller’s senses of the morality of law, I shall first outline what he means by a ‘structure’. Second, how is the structure related to legal knowledge? Third, what are the various forms of the structure? Fourth, is the structure centrifugal or centripetal? And finally, why is the structure binding?