O wad some power the giftie gie us, To see ourselves as others see us!

The unexamined life is not worth living.

The examined life is no picnic.

Go to your bosom; Knock there, and ask your heart what it doth know ...

Nothing will make us so charitable and tender to the faults of others, as, by self-examination, thoroughly to know our own.

Learn what you are and be such.

Know then thyself, presume not God to scan; The proper study of mankind is man.

... we know what we are, but know not what we may be.

You will never be an inwardly religious and devout man unless you pass over in silence the shortcomings of your fellow men, and diligently examine your own weaknesses.