The tree of Porphyrius

The Tree of Porphyry, a system of knowledge derived from the introduction of the Neoplatonic philosopher Porphyry to Aristotle’s Categories. Using a tree with its trunk and branches, the ordering of various genus and species concepts is depicted. The trunk contains the genera, the branches the two species (species or differentiae) of the genera. From top to bottom, these are the genus Substantia, with the species Immaterialis (spirit) and Materialis (body), down to the genus Anima (soul) with the species Irrationalis and Rationalis, and finally the genus Homo (man). In deviation from the ancient system of knowledge, the roots of the tree contain the names of Christ’s apostles John and Peter.