Situation-action machines are built with a bunch of rules that say, “If in situation X, do A,” “If in situation B, do Z,” and so forth. It’s as if you had a list that you kept in your wallet and when important decisions came up, you looked at the list. If the conditions for a particular decision were met, you just did it. You don’t know why. It’s just that the rule says to do it. A choice machine is different. A choice machine looks at the world and sees options, and it says, “If I did this, what would happen? If I did that, what would happen? If I did this other thing, what would happen?” It builds up an anticipation of what the likely outcome of one action or another would be, and then chooses on the basis of how much that outcome is valued or disvalued.”