 Modern philosophers also pay great attention to the privileged access cognizers have to their own cognitive activities. Augustine introduces a distinction that paves the way for this idea. He argues that the mind cannot know what kind of stuff it is (De Trinitate 10.10 and 15.12). The mind does not know its substance, but it knows its activities. For Augustine, this means that the mind knows itself. The mind is precisely what it knows itself to be: in knowing that one thinks, judges, lives, and so on, one knows the mind (Vogt 2014a). Note that this argument indicates that knowing that one lives and is are not pieces of knowledge about one’s bodily existence, but about the activities of the mind.