Date: April 26, 1695; 1708

"Meditating by one's self is like digging in the Mine; it often, perhaps, brings up maiden Earth, which never came near the Light before; but whether it contain any Metal in it, is never so well tried as in Conversation with a knowing judicious Friend, who carries about him the true Touch-stone, ...

— Locke, John (1632-1704)

Date: 1709, 1714

"We polish one another, and rub off our Corners and rough Sides by a sort of amicable Collision. To restrain this, is inevitably to bring a Rust upon Mens Understandings."

— Cooper, Anthony Ashley, third earl of Shaftesbury (1671-1713)