 An important recurring theme in the early philosophical analysis of knowledge is the paradigm of manipulating a piece of wax: either by simply deforming it, by imprinting a signet ring in it or by writing characters on it. The fact that wax can take different shapes and secondary qualities (temperature, smell, touch) while the volume (extension) stays the same, make it a rich source of analogies, natural to Greek, Roman and medieval culture, where wax was used both for sculpture, writing (wax tablets) and encaustic painting. One finds this topic in writings of such diverse authors as Democritus, Plato, Aristotle, Theophrastus, Cicero, Augustine, Avicenna, Duns Scotus, Aquinas, Descartes and Locke.