All race conditions, deadlock conditions, and concurrent update problems are due to mutable variables.

Truth can only be found in one place: the code.

The perfect kind of architecture decision is the one which never has to be made

Indeed, the ratio of time spent reading versus writing is well over 10 to 1. We are constantly reading old code as part of the effort to write new code. ...[Therefore,] making it easy to read makes it easier to write.

the fact that oo languages provide safe and convenient polymorphism means that any source code dependency, no matter where it is, can be inverted