To give expression is not to substitute, for new thought, a system of stable signs to which unchangeable thoughts are linked, it is to ensure, by the use of words already used, that the new intention carries on the heritage of the past, it is at a stroke to incorporate the past into the present, and weld that present to a future, to open a whole temporal cycle in which the 'acquired' thought will remain present as a dimension, without our needing henceforth to summon it up or reproduce it.