In response to a post on William Pora’s blog, I started to type, “Great minds think alike.” I got halfway through “think” before I deleted the line, horrified.

I don’t even want mediocre minds to think alike. But great minds, however we’d define “great?”

Please. No.

For the good of us all, let each of them think at least slightly differently.

Perhaps nonthinking people think alike, but thinking people surely do not. Thinking people use their minds for independent inquiry and bring into debate distinct perspectives from different angles. Separate minds puzzling over the same points will together develop something far superior to anything produced separately—and to any two or more people thinking exactly alike.

Frankly, I doubt the possibility of anyone thinking exactly like another person. Our brains’ analytical approaches differ due to cultural background, environment, experience, and education. Genetics wire our brains slightly differently—as an introvert, research shows that my mind processes information unlike an extrovert’s mind. Our biochemistry—which changes over the course of our days—influences our thinking, influencing our optimism and pessimism, our rapidity or sluggishness of thought, and more.

What a relief.

Turns out that though the original idiom seems to have come about in the 1600s as we know it today, over time the British updated it to add “fools seldom differ”—drilling home the irony this silly saying needs.

If you think exactly like someone else, you haven’t thought at all.