It is the thesis of the paper that the arts of the twentieth century have gone much further in the criticism of customary modes of thought than have both the sciences and the various critical philosophies which exist today. Moreover, they have not only developed an abstract principle of criticism, they have also studied the psychological conditions under which criticism can be expected to become effective. Some plays and the theoretical essays of Ionesco are analysed as an example. It is (...) pointed out that Ionesco resembles Bacon in that he believes in an unchangeable basis of humanity from which all ideologies proceed. An attempt is made to free Ionesco from these dogmatic elements, theoretically, as well as practically (i.e. as regards the performance of his plays) and to utilize to the full his contributions to a theatre that is free of prejudice, and fully critical. (shrink)