Half the opinions you defend hardest, you borrowed from someone you’ve never met.

Positions arrive through the people and feeds around you long before you examine them, and the borrowed ones are often defended hardest because there is nothing underneath to check. Conviction and origin are unrelated. You can feel absolutely certain about something you have never once thought through on your own.

Take a view you hold strongly and try to trace where it came from and what the best argument against it is. If you cannot state the other side fairly, you are holding a borrowed item. Keeping it is fine, once you have checked that it is yours.