Star Trek V: The Final Frontier had its issues as a major motion film, but it also had its memorable moments, those that stayed with the viewers long after the credits rolled. One of those scenes was when Deforest Kelley's Dr Leonard "Bones" McCoy confronts his memories of the past in a flashback scene when his father was dying.
Because his father was in so much pain, and Bones was unable to alleviate it, he disconnected his father from life support. When presented with the scene, Kelley didn't want to do it, and William Shatner, both the star and the director, had to step in and convince him that it was the best scene he'd had to play.
Captains' Logs The Authorized Complete Star Trek Voyages by Edward Gross and Mark A. Altman shares the moments that led up to Kelley's acceptance of the scene and what it took to convince him to play it.
"I said, 'De, this is the best scene you've had to play in a long time.' He's such a wonderful actor, and I really felt he hadn't had a chance recently to show what he was capable of doing. Finally, after much talking, I convinced him to do it. His one stipulation was that we add an explanation of why McCoy committed the euthanasia."William Shatner
That explanation turned out to be one of the most poignant moments of the scene. McCoy's response to why he'd done it was "to preserve his dignity." It was such a powerful explanation and one that resonates today as everyone wants death with dignity. Little did the writers and producers know that Kelley's scene would stand out for others who are going through the same struggles as they come to terms with a terminal illness. It's just one more piece of proof that Star Trek was, and always will be, ahead of its time.