“I am mad, I think. I am mad therefore I think. I am mad therefore I think I am.”

“Personally, I don’t think it right to make up things about real people—although I suppose there’s an argument for saying that once you’re dead you’re not real any more. But then we have to define what we mean by real and none of us wants to go down that tortuous path because we all know where it leads (madness or a first-class honours, or both).”

“I think I am mad sometimes.”

“I think, therefore I am, therefore I am photographable.”

“I think I am, therefore, I am... I think.”

“I think where I am not, therefore I am where I do not think. I am not whenever I am the plaything of my thought; I think of what I am where I do not think to think.”

“I doubt, therefore I think, therefore I am.”