Rational decisions.

"... the crucial fact of the world we live in is that all actions or inactions entail costs which have to be taken into account in order to reach a rational decision. 'Rational' is here used in its most basic sense - the ability to make a ratio, as in 'rational numbers' in mathematics - so that rational decisions are decisions that weigh one thing against another, a trade-off as distinguished from a crusade to achieve some 'good thing' without weighing costs."
- Thomas Sowell