Derech Eretz

Pirkei Avot teaches us that דרך ארץ קדמה לתורה, that a prerequisite to the study of Torah, is that one must have good character. He must be polite and have good manners and should be respectful of his elders.
The Chazon Ish goes a step further by explaining that one’s motivation in doing good deeds or acts of kindness, is strictly for the sake of the Mitzva.
It is written in Psalms, סור מרע ועשה טוב, “Turn away from evil, and do good.” It is possible for an individual to be driven by the “do good” part of the verse, but he has not managed to “turn away from evil.”
He gives an example of someone who will dedicate every last remnant of his strength for the good of others, both for the individual and the community. This same individual might who is very intolerant, offends people with his speech, and has a tendency towards uncontrollable anger.
All of the good that he does is ruined by his lack of “Derech Eretz” and good character traits. It is not possible to accord praise, honor, and acclaim, to such a person.
This is a good example of the need to work on one’s Midot. This was what the Chazon Ish was trying to explain as to how one is able to achieve clarity and a correct perception of the world. “Being a Mentch” is not only a recommendation. It is an absolute requirement and prerequisite for acquiring Torah and all of the things that matter in this world.