Flight from Destiny (1941)

After philosophy Professor Todhunter is told he has 6 months left to live, he is barred from teaching by his college so there won't be a scandal if he drops dead in class. Discussing a hypothetical man with 6 months to live with a group of friends, Todhunter asks each what he'd do in his last 6 months. One says he'd commit a "social murder"--kill someone who is not a criminal but society would be better off without that person anyway. The professor obsesses on the idea and actually comes across a situation involving two of his friends where he thinks that acting on his obsession would be a good idea.