The mystical language is the one appropriated a host of characters that the wavering surface of Catholicism in the modern era could no longer sustain longer. So they tried to build a grammar, a vocabulary, a special type of presence that only the rigor of an analyst and sensitivity of a poet could help restore understandably. For these mystics, Michel de Certeau, the considerable scope of the work will still be too little known, knows how to use multiple donations that made it unique in order to produce a poetic mystical fable, try to draw what he called "a formality practical." But this book reads more especially in light of our current problems as companies Michel de Certeau had seized the presence and persistence of trans-mystical word of beings from somewhere, fell into a situation of anomie. Theses Certeau on mysticism are inseparable from the poetic discourse that passes through its entire production on otherness, the difficult quest for the other, an injury, an absence from, generally conducive to undertaking. No doubt she was his Jesuit vocation there for something, but his acute issues on history and psychoanalysis deeply nourished his approach.