As the terms ‘Facebook’ and ‘YouTube’ suggest, we are increasingly experiencing our being via technologies of mediation; if Facebook implies an extension of corporeality, YouTube more complicatedly points towards an extension of our conscious self. Brian Rotman has expressed this phenomenon as a process of ‘becoming beside ourselves’, which suggests the displacement of fixed notions of being by processual notions of becoming, and the way in which these processes are taking us beyond defined notions of selfhood—from the self to the ‘selfie’. McLuhan's media theory pertains directly to this increasingly relational sense of being emerging from the mediascape through his argument that media are effecting ‘an evolutionary […] [shift] from biology to technology’ in which ‘the body becomes the old hardware environment,’ and ‘media [the] means of extending and enlarging our organic sense lives into our environment’ (The Book of Probes, pp. 111, 155).

Insights such as these derive from McLuhan's sense of media as embodied; as he put it, media are both extensions and amputations of the body and, with the computer, that process extends to consciousness itself. In conjunction with this extension theory, McLuhan developed an environmental or ecological theory of mediation, bringing the two notions together in his 1967 tour de force, The Medium is the Massage, a book that is so brilliant in terms of its design that its importance for McLuhan's thought tends to be overlooked. As Schnapp and Michaels put it in The Electric Information Age Book,