If everybody is thinking alike, then somebody isn't thinking.

If we all think alike, no one is thinking.

If everyone is thinking alike, then somebody isn’t thinking. George S. Patton

Quien no quiere pensar es un fanático; quien no puede pensar es un idiota; quien no osa pensar es un cobarde.

Where all think alike, no one thinks very much. — WALTER LIPPMANN, The Stakes of Diplomacy

A person who thinks all the time has nothing to think about except thoughts, so he loses touch with reality and lives in a world of illusions.

A person who thinks all the time has nothing to think about except thoughts, so he loses touch with reality and lives in a world of illusions.

Aprender sin pensar es inútil. Pensar sin aprender peligroso

It would be a dull world if we all thought alike.

Indeed it may be said with some confidence that the average man never really thinks from end to end of his life. There are moments when his cogitations are relatively more respectable than usual, but even at their climaxes they never reach anything properly describable as the level of serious thought. The mental activity of such people is only a mouthing of clichés. What they mistake for thought is simply a repetition of what they have heard. My guess is that well over eighty per cent. of the human race goes through life without having a single original thought. That is to say, they never think anything that has not been thought before and by thousands.

كثيرون يفكرون في تغيير العالم لكن لا أحد يفكر في تغيير نفسه.

Não tenha medo de pensar diferente dos outros, tenha medo de pensar igual e descobrir que todos estão errados.

A man who does not think for himself does not think at all.

Nobody is thinking about you the way you are thinking about you. They’re all thinking about themselves.