"To be a man's own fool is bad enough, but the vain man is everybody's"

This quote by William Penn is a caution against vanity. It recommends that it is bad enough to be a fool to oneself, however it is even worse to be a fool to everyone else. Penn is cautioning versus the dangers of vanity, which can lead to absurd decisions and habits. He is recommending that it is much better to be simple and sensible than to be vain and silly. Penn is likewise indicating that vanity can cause an absence of self-awareness and a lack of respect from others. He is alerting that vanity can cause an absence of self-control and a disrespect from others. By being vain, one can end up being a fool to everybody else, and this can cause a disrespect and an absence of success. Penn is cautioning versus the risks of vanity and is suggesting that it is much better to be humble and wise than to be vain and silly.