The Vulcan mind meld seems a curious ability for the Vulcan race to have developed. Being a people ruled by logic, Vulcans nonetheless possess passionate emotions, which they suppress. The process of mind melding leaves them vulnerable, not only to their own carefully hidden emotions, but to the emotions of others. For this reason, Vulcans consider the mind meld to be a deeply personal, private experience.

AS Spock himself once explained to Doctor Leonard McCoy, the mind meld is not telepathy. It is based on touch. By making minute pressure changes in the partner's nerves and blood vessels, a Vulcan's consciousness is able to join with that of the partner. The two minds become one, sharing thoughts, memories and sometimes even speaking together in one voice.

The uses of the mind meld vary. The first time Spock used it aboard the Constellation-class USS Enterprise, he was able to verify the identity of Dr. Simon Van Gelder, a madman who claimed to be the head ofa penal colony ("Dagger of the Mind"). Spock later used the mind meld to distract a guard beyond a locked door ("A Taste of Armageddon"); to lend confidence to his comrades ("Spectre of the Gun"); to mentally perceive the true form of a shape-shifted alien ("By Any Other Name"); to communicate with a non-vocal species ("Devil In the Dark"); and to discover his captain's consciousness trapped in another body ("Turnabout Intruder").

In the Star Trek: rhe Next Generation episode "Sarek," Captain Jean-Luc Picard entered into a mind meld with Spock's father, Sarek, who desperately needed Picard's emotional support to allay the debilitating effects of Bendii Syndrome.