The term "psychological Western" has become something of a cliche. If you had to label Fred Zinnemann's masterpiece, it should be called a neo-realist Western on account of the understated performances and Floyd Crosby's stark imagery.
Written as a rejoinder to that pro-witchhunt parable, On The Waterfront, this treatise on fidelity to principle is told in real time to add to the suspense and boasts a performance of rare grit and dignity by the finest lawman of them all, Gary Cooper.
Look out for a young Lloyd bridges as a no-good, and the Oscar winning theme song "Do not forsake me, Oh My Darlin'" is indeed the inspiration for the theme of the townsfolk in Blazing Saddles.