This chapter elaborates the importance of things for the mind. Technologies are things that are combined with a practical rationality in human practices. Mental technologies are a kind of cognitive technology that also enable various forms of human action, but which are mainly relevant for cognitive psychology. The thesis about 'the extended mind' and active externalism were indeed developed within cognitive psychology, but there is a need to thematize the significance of things and technologies in other fields of psychology as well. The figure who perhaps most strongly emphasized the technological and political aspects of the mind in the broad sense is the French philosopher and historian of ideas Michel Foucault. Not only human scientists like Foucault and Latour have been interested in the significance of things for the mind, but cultural psychologists have also analyzed mental development in light of things and artefacts.