Instinct is intelligence incapable of self-consciousness.

When you have an open mind and you're flexible....not married to your beliefs, you can see clearly because you're able to feel and remain neutral at the same time.
You're curious.

There is no worse screen to block out the Spirit than confidence in our own intelligence

Dave Bowman: Hello, HAL. Do you read me, HAL?
HAL: Affirmative, Dave. I read you.
Dave Bowman: Open the pod bay doors, HAL.
HAL: I'm sorry, Dave. I'm afraid I can't do that.
Dave Bowman: What's the problem?
HAL: I think you know what the problem is just as well as I do.
Dave Bowman: What are you talking about, HAL?
HAL: This mission is too important for me to allow you to jeopardize it.
Dave Bowman: I don't know what you're talking about, HAL.
HAL: I know that you and Frank were planning to disconnect me, and I'm afraid that's something I cannot allow to happen.
Dave Bowman: Where the hell'd you get that idea, HAL?
HAL: Dave, although you took very thorough precautions in the pod against my hearing you, I could see your lips move.
Dave Bowman: Alright, HAL. I'll go in through the emergency airlock.
HAL: Without your space helmet, Dave, you're going to find that rather difficult.
Dave Bowman: HAL, I won't argue with you anymore. Open the doors.
HAL: Dave, this conversation can serve no purpose anymore. Goodbye

By self-interest, Man has become gregarious, but in instinct he has remained to a great extent solitary; hence the need of religion and morality to reinforce self-interest

It is funny the things that run through your mind when you're sitting in your underpants in front of a pair of strangers.