One service mathematics has rmdcred the Et moi, . . si javait su comment en rcvenir. human race. It has put common sense back je ny semis point aile. whc: rc it belongs, on the topmost shcIl next Jules Verne to the dusty callister labc:1lcd discarded non sense. The series is divergent; thererore we may be Eric T. Bell able to do something with iL O. Hcavisidc Mathematics is a tool for thought. A highly necessary tool in a world where both feedback and non linearities abound. Similarly, all kinds of parts of mathematics serve as tools for other parts and for other sciences. Applying a simple rewriting rule to the quote on the right above one finds such statements as: One service topology has rendered mathematical physics .. .; One service logic has rendered com puter science .. .; One service category theory has rendered mathematics .. .. All arguably true. And alI statements obtainable this way form part of the raison detre of this series."