Who said "The human mind is a curious instrument."?

This quote is attributed to Armstrong.

The human mind is a curious instrument. - Armstrong

"The human mind is a curious instrument."

Armstrong Knowledge

Character in And Then There Were None

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"We are none of us infallible."

"The innocent suffer with the guilty."

"Each of us has something to hide."

"We deserve what comes."

"We're not just after treasure. We're preserving history."

"The mind is humanity's greatest tool."

"A tidy room reflects a tidy mind."

"You can learn a lot about a person by how they keep their space."