I've never ever known an INTP who could be idealistic in everyday life.
With that, and what I know about these doods, I can say that no, you will never be friends. Because you will never be friends, your *sole* reason for interacting with him should be professional and non-friendship related.
I say you completely cut him off, but passive-aggressively and full of flair. Invite him over to your place of residence(house, apartment, frottage cottage, ect) and rig it up fill of Home Alone style booby traps: Replace the doorbell with a thumbtack, offer him chocolate dessert flavored laxatives, and invite him upstairs for 'coffee' so as he's about halfway up a seemingly innocent bag of marbles should just so happen to find their way rolling down the stairs. During all of this make sure to sell the illusion that these are just random occurrences, and and at the end make sure to chase him and apologize profusely while he's running out your front door flailing his arms wildly while tarred and feathered with a rake handle protruding out of his anus as his screams mimic a mountain lion in heat. He'll probably still want to be friends despite all this, but chances are he'll be a bit more distant.
I fully support this plan. Incorporate itching powder.
Not type related. He's a jerk and/or emotionally volatile right now. Avoid at all costs, involve the law if necessary. Bring a friend with you when you have to meet with him. Communicate only by email whenever possible. Don't answer his calls.