In recent times, the concept of ‘intangible heritage’ has gained credence within the international heritage community, reflecting wider concerns relating to the cultural impact of global economic, technological and political forces. For many, intangible heritage represents a vital living mediation of the material past (i.e. tangible heritage) which deepens its significance and meaning-conferring qualities. This thesis explores how in recent times, the intangible heritage became ‘separated’ from the tangible heritage in such a way as to bring about ideological division within the field of heritage preservation and a sense of discontinuity with the past – particularly relating to the practice of restoration and its patrimony of expertise. The thesis argues that this has been attributable to an ‘institutionalised’ conception of heritage based essentially on a historiography of materials located in the ideological site of the museum – the repository where tangible heritage is housed, organised, interpreted, conserved, restored and displayed in such ways as to confer meaning upon the material world. By drawing extensively upon evidence from the literature and engaging the conservation-restoration field, the thesis develops discussion around the emergence (and subsequent institutionalisation) of a relatively recent scientific paradigm of practice – ‘scientific restoration’ – largely shaped by this ‘museological’ vision of heritage. It also considers how the work of Cesare Brandi came to be instrumental in the formulation of this vision but argues that such conceptions have been predicated upon a misappropriation of his ideas and a misreading of historical heritage preservation ideologies that has done much to contribute to tensions evident within the heritage community. To this end, the thesis aims to redress this historical impasse by reconsidering the function of restoration – especially in terms of what is added to the historical document – and reconciling the competing claims of the tangible and intangible by developing the concept of ‘authentic process’.