Who is Jack Parsons from Inside Scientology: The Story of America's Most Secretive Religion and what is their importance?

Jack Parsons was a self-taught chemist and explosives expert, and the leader of the rocket program for Cal Tech in 1944. Parsons was a genius, but also an eccentric with a passion for the occult. He was good friends with black magician Aleister Crowley and followed his Thelema religion seriously. It was Parsons who first introduced Hubbard to the idea of alternate religion, and it was Parsons who gave Hubbard several of the ideas he later used to develop Dianetics and Scientology. Parsons opened his house to Hubbard, along with a host of other genius eccentrics. It was Hubbard, however, who proceeded to steal his girlfriend and much of his money. When Parsons went into business with Hubbard, it was his undoing and Hubbard conned him. Parsons sold his ranch home and the two never spoke again.