Who said "Gratitude is a weakness reserved for the grateful."?

This quote is attributed to Moriarty.

Gratitude is a weakness reserved for the grateful. - Moriarty

"Gratitude is a weakness reserved for the grateful."

Moriarty Gratitude

"You see, but you do not observe. The distinction is quite clear."

"I am not a puzzle to be solved; I am the one who solves."

"The world is full of obvious things which no one by any chance ever observes."

"Crime is common. Logic is rare."

"Gratitude makes life richer."

"A grateful heart is a happy heart."

"Respect those who came before us."

"Life's greatest treasures are the people we love"