The idiomatic expression "calling a spade a spade" means to speak frankly and directly about something, even if it is unpleasant or controversial. It implies being honest and forthright in one's opinions and actions without worrying about the consequences or how others might perceive them. The phrase originated from an ancient Roman proverb "Qui facit per alium facit per se" which means "He who does something through another, does it himself."