Those friends thou hast, and their adoption tried,
Grapple them to thy soul with hoops of steel;
But do not dull thy palm with entertainment
Of each new-hatch'd, unfledg’d comrade. Beware
Of entrance to a quarrel but, being in,
Bear't that th' opposed may beware of thee.
Give every man thy ear, but few thy voice;
Take each man's censure, but reserve thy judgement.
Costly thy habit as thy purse can buy,
But not express'd in fancy; rich, not gaudy;
For the apparel oft proclaims the man;
And they in France of the best rank and station
Are of a most select and generous chief in that.
Neither a borrower, nor a lender be;
For loan oft loses both itself and friend,
And borrowing dulls the edge of husbandry.
This above all: to thine own self be true,
And it must follow, as the night the day,
Thou canst not then be false to any man.
Farewell; my blessing season this in thee!
William Shakespeare - Hamlet Act 1 Scene iii