I've always believed that a true born again child of Christ cannot be possessed by a demon. They have been "sealed" by Gods blessed Holy Spirit. Oppressed, yes...... Possessed, no way."Can angels know what I'm thinking telepathically" - Aquinas says an angel (or demon) cannot read your mind against your will. It's not your mind, but your will that determines whether the angel (or demon) can read your thought. A devil cannot possess you or even understand what your thinking without you somehow giving consent. Angels can influence your imagination, but not your thought. Your thought which is controlled by your will, is your inner sanctuary, so when you pray to your guardian angel, whether verbally or nonverbally your opening the door of that inner sanctuary. Your guardian angels are perfect telepaths who know when you're doing that. And its the same with demons, you open your sanctuary if you are praying to them, if you consent to them.
The mind is incredibly complex as you've indicated in your article. I would also say, it's part of the reason pornography and watching inappropriate things is so destructive. The memory is tied to the imagination. It's as though you gave them consent into your memories which, I believe, they can potentially rekindle. Them influencing your imagination via memories is not giving consent or the same thing as praying and willingly opening yourself to them. In the past you may have unknowingly consented in some way or opened yourself up in some way, but if you've been to confession and renounced this then have faith in God.
"St. Thomas distinguishes two kinds of memory, sensory and intellectual. He excludes, however, from the former the function of merely storing up the mental image; this he assigns to imagination."
Sensory memory he assigns to the body; so think muscle memory. While Intellectual memory is tied to the abstract and universal. As far as the body is concerned and ridding yourself of the temporal / transitory sin attached to the body. Ascetic practices are efficacious because it purges sensory memory tied to the body. Prayer is efficacious because it purges intellectual memory tied to the abstract.
A good simple helpful way around this I was told, is to disregard the images or thoughts instantly if evil. Don't dwell on them or think about them. God doesn't want you to think evil things, and so evil ideas should be ignored and not given weight or merit.
Possession is rare as far as I know, but maybe it's more common than we realize. Diabolic oppression is most likely far more common. Being harassed by evil thoughts or spirts is going to happen if you're on the side of Christ. St Teresa of Avila considered them like flies, satan afterall is 'Lord of the Flies', and so if you have Christ and are doing the right things generally speaking you'll be 'fine'. It's when people engage in the occult and drugs and pornography and all the rest of it which destroys the body and soul. Demons do not attack a fortress if its already been captured and so oppression of some kind is probably inevitable at some point if you are on the right path, but I wouldn't 'overthink' it. It's easy to get carried away with ideas and let your imagination run wild.
I personally think everyone needs to purge themselves at some point and or go on some kind of pilgrimage, or retreat and fast and pray like Christ did in the desert for at least a month. Most people nowadays don't realize how much sin is in their homes and minds and lives. I would encourage everyone to find a good Priest or spiritual director and at very least devote a month or so to redirecting your entire life and mind back to God if you haven't already.
Anyways interesting article, thanks for sharing as always.