Lisa Rein from the Timothy Leary estate writes,

Dr. Timothy Leary Futique Trust has released two letters from its archives from Carl Sagan, written to Tim Leary in the Spring of 1974. Turns out that Sagan visited Leary in prison at least once.

There are more than a few remarkable similarities when the lives of these two visionaries are compared. They were both scientific explorers and cultural activists – men of ideas and of action. They were geniuses at communication,

not only in their books and talks, but as showmen, with extraordinary ability to

spread their ideas to a mass audience.

Leary was the era's foremost advocate of inner space exploration, through humanistic psychology and mind-altering drugs, whereas Sagan was the highest profile advocate of space exploration and extra-terrestrial communication. Both were adept at using the media to illuminate their big ideas about inner space (Tim) and outer space (Carl).