Strength of mind

It is an unconquerable strength of mind, knowing the world well, gentle in its dealings, showing great courtesy and consideration for those with whom it is brought into contact.

On the happy life by Seneca 

Quote about the learned

It is a right proposition of the learned that at all times people believed they knew what is good and evil, laudable and reprehensible. But it is a prejudice of the learned to pretend that our knowledge in these matters excelled that of any previous age. 

The dawn of day by Friedrich Nietzsche 

Quote about the learned