It is important to remember that education and literacy is something that the creature Frankenstein creates is forced to learn himself by eavesdropping on the lessons that Felix gives to Safie and the actions of this family that he, unknown to them, adopts as his own. Note what the creature says to Frankenstein about how he learnt so much through simply listening to the conversation of this household:
Every conversation of the cottagers now opened new wonders to me. While I listened to the instructions which Felix bestowed upon the Arabian, the strange system of human society was explained to me. I heard of the division of property, of immense wealth and squalid poverty; of rank, descent, and noble blood.
What is fascinating about this process of education and literacy however is that it allows one who is not entirely a man to learn about the society and culture of man as an outsider with his own unique perspective. In this sense, education and literacy enables the creature to ask some very harsh questions about humanity and the inconsistencies in us as creatures:
Was man, indeed, at once so powerful, so virtuous and magnificent, yet so vicious and base? He appeared at one time a mere scion of the evil principle, and at another as all that can be conceived of noble and godlike... For a long time I could not conceive how one man could go forth to murder his fellow, or even why there were laws and governments; but when I heard details of vice and bloodshed, my wonder ceased, and I turned away with disgust and loathing.
Education and literacy thus enables the creature to learn about the world of man and to judge it harshly, indirectly allowing the author to present the inconsistencies of our species to us. Man, on the one hand is so culturally refined and so noble a creature. And yet, on the other hand, is capable of committing terrible acts of bloodshed and torture that appall those around them. This highlights the fact that if the creature does commit heinous crimes, it is only because he is modeling the kind of attitudes that men have exhibited to him.