Kolinahr is a Vulcan discipline wherein all emotion is renounced and shed. What remains is a state of pure logic.

From the film:

Star Trek: The Motion Picture
Stardate: 7410.2
Original Airdate: Dec 20, 1979

FEMALE MASTER: (in Vulcan) Our ancestors cast out their animal passions on these very sands, …saving our race through the attainment of Kolinahr.
MALE MASTER: (in Vulcan) Kolinahr, through which all emotion is renounced and shed.
FEMALE MASTER: (in Vulcan) You have laboured for many seasons, Spock …and you have proved yourself worthy …to receive this symbol of pure logic.
(Spock stops her putting the ancient pendant around his neck)
FEMALE MASTER: (in Vulcan) Your thoughts, give them to me. Our minds are joined, Spock, …together, and as one. I sense the consciousness calling to you from space. …Your human blood is touched by it, Spock. You have not yet attained Kolinahr. He must search elsewhere for his answer. He shall not find it here. Live long and prosper, Spock.