“The worst sin... is... to be indifferent.”
“Pain has its reasons, pleasure is totally indifferent.”
“A different world cannot be built by indifferent people.”
“Men are accomplices to that which leaves them indifferent.”
“Lukewarmness I account a sin, as great in love as in religion.”
“It means nothing to me. I have no opinion about it, and I don't care.”
“Nothing can contribute more to peace of soul than the lack of any opinion whatever.”
“The worst sin towards our fellow creatures is not to hate them, but to be indifferent to them; that's the essence of inhumanity.”
“Wherever the citizen becomes indifferent to his fellows, so will the husband be to his wife, and the father of a family toward the members of his household.”
“Only one enemy is worse than despair: indifference. In every area of human creativity, indifference is the enemy; indifference of evil is worse than evil, because it is also sterile.”
“The opposite of love is not hate, it's indifference. The opposite of art is not ugliness, it's indifference. The opposite of faith is not heresy, it's indifference. And the opposite of life is not death, it's indifference.”
“I have protracted my work till most of those whom I wished to please have sunk into the grave, and success and miscarriage are empty sounds: I therefore dismiss it with frigid tranquillity, having little to fear or hope from censure or from praise.”