I ns ti t ut Gal i lé e - U niv. P ar is - Nord 93430 V il l et ane us e - F RA NC E noui ouaf @l ipn.uni v-pa ri s 13.fr G eneral ly s peaking, form al NL s em antic s i s re ferenti al i .e. it as sum es t hat i t is pos si ble t o c reate a s tati c dis course uni verse and to equat e t he obj ect s of t his uni verse t o the (s tat ic) mea nings of w ords . The me aning of a sent ence is then buil t from t he me anings of the w ords in a c ompos iti onal proces s and the se mant ic inte rpretat ion of a s entenc e i s reduce d to it s logic al i nterpret ati on bas ed on t he t ruth condit ions . The very diffic ult tas k of ada pting the mea ning of a s ent ence to its c ontext is often left to the pragm ati c l evel, and this tas k re quires t o us e a huge a mount of com mon s ens e know ledge a bout the domai n. It has bee n s howe d t hat the above tri-pa rtit ion i s very arti fici al becaus e l inguis ti c a s we ll as e xtra-li nguis tic know ledge i nterac t i n t he s am e gl obal proces s to provide the ne ces sa ry elem ents for unders ta nding. But what kind of rea soni ng is needed for na tural language se manti cs? T he ans we r to thi s que st ion is bas ed on the remark t hat t exts s eldom provide norma l det ail s t hat are a ss umed to be known to the reader.