It looks like there's all this undefined behavior, and demons coming out the nose from the outside because you aren't looking at the exact details of what's going on in with their feelings that are choosing the beliefs. Though a C compiler given an undefined construct may cause your program to crash, it will never literally cause demons to come out of your nose, and you could figure this out if you looked at the implementation of the compiler. It's still deterministic. As an atheistic meta-ethical ant-realist, my utility function is basically whatever I want it to be. It's entirely internal. From the outside, from someone who has a system where they follow something external and clearly specified, they could shout "Nasal demons!", but demons will never come out my nose, and my internal, ever so frighteningly non-negotiable desires are never going to include planned famines. It has reliable internal structure. The mistake is looking at a particular kind of specification that defines all the behavior, and then looking at a system not covered by that specification, but which is controlled by another specification you haven't bothered to understand, and saying "Who can possibly say what that system will do?" Some processors (even x86) have instructions (such as bit rotate) which are useful for significant performance boosts in stuff like cryptography, and yet aren't accessible from C or C++, and to use it you have to perform hacks like writing the machine code out as bytes, casting its address to a function pointer and calling it. That's undefined behavior with respect to the C/C++ standard. But it's perfectly predictable if you know what platform you're on. Other people who aren't meta-ethical anti-realists' utility functions are not really negotiable either. You can't really give them a valid argument that will convince them not to do something evil if they happen to be psychopaths. They just have internal desires and things they care about, and they care a lot mo