Why does the idea of progress 【A21】______ so large in the modern world? Surely because progress of a【A22】______ kind is actually taking place around us and is becoming more and more 【A23】______. Although mankind has 【A24】______ no general improvement in intelligence or morality, it has made【A25】______ progress in the accumulation of knowledge.

Knowledge began to increase as soon as the thoughts of one individual could be communicated to another by means of 【A26】______. With the invention of writing, a great advance was made, for knowledge could then be not only communicated but also 【A27】______. Libraries made education possible, and education in its【A28】______ added to libraries: the growth of knowledge 【A29】______ a kind of compound interest law, which was greatly 【A30】______ by the invention of printing. All this was【A31】______ slow until, with the coming of science, the tempo was suddenly【A32】______. Then knowledge began to be accumulated according to a【A33】______ plan. The trickle became a stream; the stream has now become a 【A34】______. Moreover, as soon as new knowledge is【A35】______, it is now turned to practical account. What is called “modern civilization” is not the result of a【A36】______ development of all man’s nature, but of accumulated knowledge【A37】______ to practical life. The problem now 【A38】______ humanity is: What is going to be done with all this knowledge? As is so often pointed out, knowledge is a【A39】______ weapon which can be used equally for good and evil. It is now being used【A40】______ for both.