Man has always learned from the past. After all, you can't learn history in reverse!
Eureka! (I have found it!).
Eureka! [I have found it!] On discovery of a method to test the purity of gold.
How many theorems in geometry which have seemed at first impracticable are in time successfully worked out!
Those who claim to discover everything but produce no proofs of the same may be confuted as having actually pretended to discover the impossible.
Give me but a firm spot on which to stand, and I shall move the earth.