“A hundred suspicions don't make a proof.”
“I don't know if you know it, J.B., but you're the sort of fellow who causes hundreds to fall under suspicion when he's found stabbed in his library with a paper-knife of Oriental design.”
“I don't know. A proof is a proof. What kind of a proof? It's a proof. A proof is a proof, and when you have a good proof, it's because it's proven.”
“there are some persons in this world, who, unable to give better proof of being wise, take a strange delight in showing what they think they have sagaciously read in mankind by uncharitable suspicions of them.”
“For those who believe, no proof is necessary. For those who don't believe, no proof is possible.”
“I don't believe anything, but I have many suspicions.”