پیشگیری شرط عقل

An ounce of discretion is worth a pound of wit

Or

An ounce of prevention (is worth a pound of cure)

(یک ذره پیشگیری بهتر از یک عالمه درمان است)

Or

Prevention is better than cure

 

used to say that it is better to prevent a problem before it happens than to try to solve it after it has happened.