Spock (played by Leonard Nimoy) in the Star Trek universe would often share his logical thinking in critical situations without a hint of emotion.

How could Spock be so sure that the Talosians would ... After all the Talosians had a goal to manipulate alien species into procreating to repopulate their surface-dead planet.

Nimoy was the first actor to play a Vulcan, so he more or less co-invented the species. When Nimoy stepped in to direct "The Search for Spock," he was finally able to communicate to other actors ...