"I said the other day that the most tragic thing in the world is a sick doctor. I was wrong. The most tragic thing in the world is a man of genius who is not also a man of honor."
Ridgeon says this about Louis just after he has passed away. It is an ironic statement as Ridgeon has acted without honor for passing Louis' treatment on to Bonington knowing that he won't be able to cure him. You see, Ridgeon too is a man of genius having developed a cure for tuberculosis. He can judge another man, but cannot recognize his own rot in this.
"That voice sounded devilish. Take care, Ridgeon: my ears hear things that other people's can't. I've been thinking--thinking. I'm cleverer than you imagine."
Louis says this after hearing Ridgeon's tone in response to his asking if everyone is in the room with him. Louis lay dying, but he is as sharp as ever and knows what Ridgeon has done, more importantly why he has done it: to marry Jennifer.
"It's a little hard on a lad to be killed because his wife has too high an opinion of him. Fortunately few of us are in any danger of that."
Sir Patrick says this to Ridgeon once Ridgeon reveals he is in love with Jennifer and wants to allow Louis to die so that he may marry his widow. Sir Patrick is speaking specifically about the fact that Louis has deceived Jennifer about his honor, that he has been married to another woman while married to her and how he constantly takes money from other people without her knowing it. He is also telling Ridgeon that it is not good to allow Louis to die because the doctor wants to marry Jennifer.
