Chapter 2 On e & ex
By trying and erring, by groping and stumbling — so progressed our knowledge. Hampered and yet spurred by a hard struggle for existence, a plaything of his environment and slave to the traditions of his time man was guided in this progress not by logic but by intuition and stored up experience of his race. This applies to all things human, and I have made painstaking efforts to show that mathematics is no exception.
— Tobias Dantzig
The number e or the function ex was not a sudden creation made by a genius. The human race took a long time to detect the entity of e in a rather veiled form in some commercial activities. Later on, people observed the presence of the same entity in different natural processes. ...