The main argument of this chapter is that another distinguishing feature of technology lies in the role that technological artefacts play in extending human capabilities. However, the sense in which I understand technology to extend human capabilities requires a fair amount of clarification. In order to provide this, I need to distinguish the argument I am making from similar ideas that exist in the philosophy of technology literature. The literature I have in mind here is that in which technology is conceived of as the more or less direct extension of human faculties. Specifically, I first discuss some prominent extension theories, including the classic accounts of Ernst Kapp and Marshall McLuhan as well as some more recent contributions. The intention is not only to clarify the sense of extension I have in mind but also to introduce some ideas that I return to later on. In the second section, I try to integrate these extension ideas into the general conception of technology developed in the previous two chapters before finally drawing out some implications of the account I defend. To repeat, the main task is to indicate how the idea of extension acts to mark off, at least partially, technological from other artefacts, along with suggesting some of the benefits that follow from such a demarcation.

Extension Theories of Technology

By extension theory, I mean any theory in which technological artefacts are conceived of as some kind of extension of the human organism by way of replicating, amplifying, or supplementing bodily or mental faculties or capabilities. This basic idea of extension recurs throughout the study of technology and is found in discussions of technology that go back at least as far back as Aristotle. The more systematic treatments tend to emphasise one or more of three features: a focus upon the direct, often very mechanical, extension of ‘physical’ faculties; a focus upon the extension of cognitive (especially information processing) capabilities; the extension of human agents’ ‘will’ or intentions. I shall illustrate each feature by briefly referring in turn to the work of Ernst Kapp, Marshall McLuhan and David Rothberg.

The first occurrence of a detailed and sustained example of an extension theory is that provided by Ernst Kapp (1877).