Too much zeal spoils everything.
Zeal is like fire: it needs both feeding and watching.
Zeal is very blind, or badly regulated, when it encroaches upon the rights of others.
Let a good person do good deeds with the same zeal that an evil person does bad ones.
Zealous men are ever displaying to you the strength of their belief. while judicious men are showing you the grounds of it.
Zeal is fit for wise men, but flourishes chiefly among fools.
Never let your zeal outrun your charity. The former is but human, the latter is divine.
Through zeal, knowledge is gotten; through lack of zeal, knowledge is lost.
Experience shows that success is due less to ability than to zeal. The winner is he who gives himself to his work body and soul.
Zeal without knowledge is the sister of folly.
Zeal without humanity is like a ship without a rudder, liable to be stranded at any moment.
Zeal without knowledge is fire without light.