The state of being insane; unsoundness or derangement of mind; madness; lunacy.
Such a mental condition, as, either from the existence of delusions, or from incapacity to distinguish between right and wrong, with regard to any matter under action, does away with individual responsibility.
Insanity: doing the same thing over and over again and expecting different results. Albert Einstein
Insanity is knowing that what you're doing is completely idiotic, but still, somehow, you just can't stop it. Elizabeth Wurtzel
The distance between insanity and genius is measured only by success. Bruce Feirstein
I realize that I live on the bubble of insanity. I feel the weight of human suffering, loneliness and despair on me all the time. It's not getting easier; if anything, it's always right on the edge of my skin. Erwin McManus
'Hamlet' is one of the most dangerous things ever set down on paper. All the big, unknowable questions like what it is to be a human being; the difference between sanity and insanity; the meaning of life and death; what's real and not real. All these subjects can literally drive you mad. Michael Sheen