297. Amīr al-mu’minīn, peace be upon him, said: How many are the objects of lessons, but how few the taking of lessons. 
 If the vicissitudes and changes of this world are observed, the circumstances and condition of the people attended to and their histories noted, then from every corner edifying stories can be heard which are fully capable of arousing the mind out of its forgetful slumber, of providing instruction and of imparting teaching and clear mindedness. Thus, the creation and dissolution of every thing in this world, the blossoming of flowers and their withering, the thriving of vegetation and its withering away and the subjugation of every atom to change are such instructive lessons that they are enough to curb any hope of attaining eternity in this deceitful life as long as the eyes and ears are not closed to these instructive events.
A Persian couplet says : The world is full of stories of folk gone by, but unless one lends an ear to it, its call is weak.