293. Amīr al-mu’minīn, peace be upon him, said: Do not associate with a fool because he will beautify his actions before you and long that you too be like him. 
 A fool considers his ways of action appropriate, and wants his friend also to adopt the same ways, so that he should become as he himself is. This does not mean that he desires that his friend should become as foolish as he is. He cannot be thinking like this, because he does not consider himself foolish. If he in fact considered himself foolish, then he would not have been foolish. Instead, he considers his ways of action as correct, and desires his friend to be equally “wise”. That is why he presents his view before him in an embellished form and desires him to act upon it. It is possible his friend may be influenced by his advice and tread on the same path. Therefore, it is better to keep away from him.