"[The infinitely small] neither have nor can have theory; it is a dangerous instrument in the hands of beginners [ ... ] anticipating, for my part, the judgement of posterity, I would dare predict that this method will be accused one day, and rightly, of having retarded the progress of the mathematical sciences."

Previous Quote

Qian Xuesen, the father of the Chinese Space Program, studied in the United States, and he was a protégé of Theodore Von Carmen's at Cal Tech and helped start the jet propulsion laboratory there, and then he got caught up in the anti-communism wave and was accused of being a spy and was actually deported back to China where he built from nothing, their entire missile and space program. So, in a way, in a very real way, the United States in trying to protect so-called protect our secrets and throwing this guy out of the country, we helped seed and start the Chinese missile program.

— Leroy Chiao