The classic paper "More is Different"[1] is another good essay that touches on this subject, and opens with some really interesting examples showing why it can

The classic paper "More is Different"[1] is another good essay that touches on this subject, and opens with some really interesting examples showing why it can be hard to apply low-level laws to anticipate the behaviour of complex systems, even when you can prove that the complex systems must obey those laws. 1 - http://robotics.cs.tamu.edu/dshell/cs689/papers/anderson72more_is_different.pdf http://robotics.cs.tamu.edu/dshell/cs689/papers/anderson72mo...