My editor asked if anyone had developed the "rhetorical tetrahedron" before, basically a 3D rhetorical triangle, with more surfaces for more possibilities.
3 traditional features, logos-pathos-ethos (or writer-reader-purpose) would still exist along the sides, where they would occupy not a point but a continuum (i.e., multiple writers or multiple audiences).
However the 4 faces might offer more, such as adding kairos to the mix.
For instance, the three vertices of where the planes come together could also integrate medium, genre, and design (or whatever other terms you want to use).
Ultimately, it's just another device with which to think about rhetoric.
