“Knock yourself out… Or rather, don't.”

Variant in other editions: Do not think of knocking out another person's brains, because he differs in opinion from you; it will be as rational to knock yourself on the head because you differ from what you thought ten years ago.
The Dignity of Human Nature (1754)

Source: Catching Fire

As noted in "Ray Lewis finds motivation in disrespect" https://archive.is/yCnN8 (11 August 2005), by Jarrett Bell, USA Today.
2000s, 2005

The Different Planet Tour (1996)

Source: Forever Princess

Source: Bullet

Interview with Roy Howard of the United Press of America (28 September 1916), quoted in The Times (29 September 1916), p. 7
Secretary of State for War
Context: The British soldier is a good sportsman. He enlisted in this war in a sporting spirit—in the best sense of that term. He went in to see fair play to a small nation trampled upon by a bully. He is fighting for fair play. He has fought as a good sportsman. By the thousands he has died a good sportsman. He has never asked anything more than a sporting chance. He has not always had that. When he couldn't get it, he didn’t quit. He played the game. He didn’t squeal, and he has certainly never asked anyone to squeal for him. Under the circumstances the British, now that the fortunes of the game have turned a bit, are not disposed to stop because of the squealing done by Germans or done for Germans by probably well-meaning but misguided sympathizers and humanitarians... During these months when it seemed the finish of the British Army might come quickly, Germany elected to make this a fight to a finish with England. The British soldier was ridiculed and held in contempt. Now we intend to see that Germany has her way. The fight must be to a finish—to a knock-out.

In response to Artem Lobov's challenge prior Interview prior Fight Night Nashville https://www.youtube.com/watch?v=FKDA6hzolGU|