Curse of the Demon (1957, UK) (aka Night of the Demon)

In Jacques Tourneur's fourth true horror film (a fantasy horror thriller), an intelligent and thoughtful adaptation of the original ghost story "Casting the Runes" by noted practitioner Montague R. James - about a US psychiatrist's investigation into a Satanic cult in England:

• the ominous opening voice-over narration, heard over views of the ancient ruins of Stonehedge: "It has been written since the beginning of time, even unto these ancient stones, that evil supernatural creatures exist in a world of darkness. And it is also said man using the magic power of the ancient runic symbols can call forth these powers of darkness, the demons of Hell. Through the ages, men have feared and worshipped these creatures. The practice of witchcraft, the cults of evil have endured and exist to this day"
• the early sequence of the death of scientist and Professor Henry Harrington (Maurice Denham) after meeting with suspected devil cult leader Dr. Julian Karswell (Niall MacGinnis) - as Harrington drove into his home's car garage, a demonic figure emerged from the woods and scared him and he accidentally reversed his car into an electrical pole and was electrocuted by live wires as he exited his vehicle, and his body was mutilated by the beast
• the film's theme - the dramatic conflict between two world-views as represented by skeptical American psychiatrist Dr. John Holden (Dana Andrews) (who didn't believe in witchcraft and devil cults and was in England to debunk the supernatural) and the occultist warlock leader Dr. Julian Karswell
• in the scene set at an annual Halloween party held at Karswell's country estate, the sinister cult leader (dressed as a clown to entertain the children) expressed his views to Holden: "Do I believe in witchcraft? What kind of witchcraft? The legendary witch that rides on the imaginary broom? The hex that tortures the thoughts of the victim? The pin stuck in the image that wastes away the mind and the body?" Holden answered: "Also imaginary"; Karswell continued: "But where does imagination end and reality begin? What is this twilight, this half world of the mind that you profess to know so much about? How can we differentiate between the powers of darkness and the powers of the mind?"
• to prove his words in the following sequence, Karswell removed his hat and pinched his forehead - soon after, a violent wind storm was summoned or conjured up; after retreating to the indoors, Holden spoke to Karswell: "I didn't know you had cyclones in England!" and Karswell replied: "We don't"; Karswell predicted that Holden would die in three days (Holden was unaware that a ancient parchment passed to him, originally in Harrington's possession, held a curse written in runic script on his life)
• Holden's statement of his skepticism about black magic, the paranormal, superstition, and Harrington's unexpected death; he also spoke of his doubts about the single-most important link that could prove Karswell's involvement in the Professor's death - the character of accused murderer Rand Hobart (Brian Wilde) who had recently and coincidentally become catatonic: "The whole question of this demon monster that you think shocked Hobart out of his mind is a perfect example of auto-suggestion and mass hysteria. Just the same as flying saucers. Someone imagines that they see moving lights in the sky. And the next thing, a thousand hysterical witnesses turn up all over the world swearing that Martians are attacking us. And now, this nonsense. It even affects serious men like yourselves. Sometimes even me. But logic -- the reality of the seeable and the touchable -- that's what convinces me finally. Certainly not rumor or intuition or funny feelings"
• later, he told Joanna Harrington (Peggy Cummins), the dead professor's niece: "Nobody's free from fear. I have an imagination like anyone else. It's easy to see a demon in every dark corner. But I refuse to let this thing take possession of my good senses. If this world is ruled by demons and monsters, we may as well give up right now"
• the dark sequence of Dr. Holden sneaking into Karswell’s country estate house, when an ordinary small house cat was transformed into a predatory panther that attacked
• after leaving Karswell's home, the eerie, atmospheric and scary scene of Dr. Holden pursued by a flaming ball of smoke in the forest
• in the concluding scene at a Southampton train station, Holden was able to return the ancient parchment into Karswell's pocket; when the piece of paper escaped from Karswell's hands, he chased after it as it blew in the wind along train tracks - it cursed him and doomed him to death at 10 pm - this was the scheduled time for Holden's predicted death, now transferred to Karswell; after the paper burned to combustible ash against one of the rails, it transformed into a monstrous 30 foot demon and Karswell appeared to be attacked as a train raced by

Attack on Karswell Along Southampton Train Tracks After The Parchment With Curse Combusted

• after witnessing the terrible accident (or attack), Joanna gave an opinion to Dr. Holden about what had just happened: "Maybe it's better not to know"; after train officials announced: "The train must have hit him," Holden agreed with Joanna in the film's final line that they shouldn't try to figure out what had happened: "You're right. Maybe it's better not to know"