KIRK: Gentlemen, I'll decide.
[Kirk's quarters]
KIRK: Captain's personal log, stardate 4309.2. We have established that the thing which destroyed the U.S.S. Intrepid and the Gamma 7A system is an incredibly huge but simple cellular being whose energies are totally destructive to all known life. Both Mister Spock and Doctor McCoy have volunteered to go in a specially equipped shuttlecraft to penetrate the cell, find a way to destroy it, and free the ship. Doctor McCoy has the medical-biological knowledge. Mister Spock is better suited physically and emotionally to stand the stress. Both are right, both are capable, and which of my friends do I condemn to death? This is the captain. Mister Spock, Doctor McCoy, report to my quarters immediately. Kirk out.