Non-existence of free will. I’ve held this one for a long time, and I think it’s one that generally rubs people the wrong way and for that reason it comes off as contrarian. I am not sure that I am a determinist per se, but I do believe that free will implies that there is something “spiritual” that isn’t just some combination of nature and nurture that guides our actions. There may be randomness in our actions, but I don’t think that satisfies what I would consider to be free will. From this follows naturally another idea that is somewhat controversial that I also believe: consciousness is not a distinct thing that exists outside of the physical material of the body.