It has become a common practice within our chemistry department to use quotations of various sorts as the signature files at the end of ones emails. I believe that this is a good way for the sender to make a subtle statement without being intrusive to the sender. The signature file is located after the message and the receiver never has to read it. But, I digress.
Quotations are a powerful tool.
Once created, they can long outlive their authors and in many cases are their author's only legacy, for good or for bad. I have to acknowledge Mark Twain as the greatest orator of all time. He is the author of many famous sayings and a few of my favorites. When you sit on a red-hot cinder a second seems like an hour. A scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die and a new generation grows up that is familiar with it.