The many valuable studies on Old French spirituality which we possess do not consider the higher spirituality par excellence, namely mysticism. The reason for it is evident: We have only a few Old French mystical texts, none of them presenting an adequately recognizable system. Consequently the meaning of the words and metaphors used there remains obscure, if there are no Latin parallel texts whose semantic implications are more evident. But even if Latin parallels help to a certain extent to clear up the meaning, there remains one fact which characterizes not only the Old French medieval mystical texts, but the German, Italian, and English ones as well. The popular mystical texts are vague and not as well organized as the texts of the Schoolmen, whose clear terminology generally contains a more precise expression of the Ineffable. The whole interest of the linguist lies in discovering how a young vernacular language competes in expressivity with the Latin of the theologian, and what it can achieve. The fact that a mystical literature in any vernacular comes into being, always means that experimental mystics tell others of their experiences, or that pious souls yearn for this religious experience of a direct contact with the Divinity after having understood the lore of those experimental or real mystics. For the linguist, of course, it makes no difference—as it does for the theologian or the psychologist—whether the mystical text comes from real or would like to be mystics. The latter in their urge can be poetically and lingusitically more creative than the former who, though religious geniuses, may turn out to be poor language makers.