Star Trek’s third season will emphasize the Vulcan philosophy of universal brotherhood via an unusually shaped medallion that
Mr. Spock will receive from home and begin to wear. Its design reflects the Vulcan belief that the greatest joy in all creation is in the infinite ways that infinitely diverse things can join together to create meaning and beauty.
— Gene Roddenberry; 1968 (The Making of Star Trek)
The IDIC was originally intended to be introduced in the first episode of season three,
