Fourth Law of Sane Personal Computing
Compilation is to be considered a form of caching, and thus shall happen solely behind the scenes, like all other forms of caching. (See: the Third Law.) The machine is to accept no externally-introduced executable code except in the form preferred for making modifications (i.e. source.) All executable code visible during any kind of debugging session or accessible to the user/programmer in any other way shall also be exclusively of this form. Nothing residing at any lower levels of abstraction shall be semantically relevant to the machine's operation. In effect, the machine behaves exactly like a "hardware interpreter" of a high-level programming language. Note that what the silicon actually does to achieve this is irrelevant so long as no programmer need ever be made aware of just how it does it.
Personal computer operating systems known to obey this law:
0 (but possibly SEAForth) [*]
Notes and observations:
If you think this is nonsensical, see if this, this, or this will change your mind. The depth of the lowest semantically-relevant level of complexity in a system matters.
To be continued.
[*] Corrections are welcome.
An interpreter+JIT compiler fits that definition. I don't know of any system that does this (it's all usually byte-code VM doing JIT compilation, even for JavaScript in the web browser).