It is the mark of an educated ...

It is the mark of an educated mind to be able to entertain a thought without accepting it.
It is the mark of an educated mind to be able to entertain a thought without accepting it.

More phrases

I've missed more than 9000 shots in my career. I've lost almost 300 games. 26 times, I've been trusted to take the game winning shot and missed. I've failed over and over and over again in my life. And that is why I succeed.
I am fond of pigs. Dogs look up to us. Cats look down on us. Pigs treat us as equals.
Government of the people, by the people, for the people, shall not perish from the Earth.
The ballot is stronger than the bullet.
In times of change, learners inherit the earth, while the learned find themselves beautifully equipped to deal with a world that no longer exists.

Quotes from the same author

Change in all things is sweet.
Well begun is half done.
In all things of nature there is something of the marvelous.
Happiness depends upon ourselves.
Wishing to be friends is quick work, but friendship is a slow ripening fruit.