As a working definition, evil is the will to intentional badness.
And badness is the will to intentional evildoing?
Generally, I would agree with your emphasis on intention.
Two thoughts, though:
1. With the emphasis on intention, we can constitute "evil" only in ourselves, not in others.
2. In my experience, it is extremely rare that people do something with the intention of willing bad onto others. Usually, they have a different, positive motive and knowingly or unknowingly accept the bad effects as by-products.
You can't be an evil person without consciously and intentionally willing something bad upon someone else.
This may be a useful thought for someone who feels that judging an entire person good or evil is a good idea.
There is also no such thing as an intrinsically or objectively bad thing or event; something is only evil by intentionality, by subjectivity.
Yes, that´s what your definition says.
I do not, however, agree that this is the only criterium when judging things or events good or bad. E.g. another way to make this distinction is from the effect of the thing or event. Although this criterium doesn´t render "good/bad" necessarily "objective", at least it renders them measurable and detectable - without requiring the observer to make assumptions about the intentions of other people.
Another distinction should be made between an evil person and evil actions: the former is a person whose intentionality has become such that he constantly wills badness on others, whereas anyone can commit evil actions intermittently.
Maybe I am too optimistic or something, but I think people of the first category don´t even exist.
What causes someone to be evil? We often speak about this like people choose evil just for the heck of it, or are evil because they differ ideologically or culturally than us. But I think what motivates evil is accumulated perceived injustices in a person's life which the person displaces onto others in a decontextualized way. "The world screwed me over, and so I'll screw the world over back," is the motto for evil. One commits evil as a way of punishing others for the unfairness that the self perceives has been done to it, not just from the particular other but also additional instances of injustice done by others as well. Evil often involves overpaying the other person in badness given this displacement, and this is one of the big problems of evil: it repays too much badness on a single person at any given time. Hence, perhaps, the "blindness" involved with evil. Think about the people who grow up in bad homes or neighborhoods. They're much more likely to commit evil actions because they've had more accumulated injustices thrown their way.
1. Substantiation for the last claim is needed. Either you are preassuming that those "accumulated injustices" that they react to were not "evil", by your definition, and that the reactions are "evil", by your definition (which would be quite an assumption to make); or - in case you allow for the possibility that those "accumulated injustices" had been themselves "evil" actions, and that the reactions aren´t necessarily "evil" - there remains little space for your idea that "evil" is more widely spread in "bad homes and neighborhoods".
2. It seems to me that "injustices" is too narrow and too abstract a description of the perception that leads to such reactions. "Evil" actions (in your definition) can be committed without any thought or concept of "(in)justice" quite fine. They just require you to e.g. want something badly - the abstraction "justice" needn´t even cross your mind.
Another way of saying this is that evil would be impossible without a standard of justice.
Disagree.
Twice I have done something evil by your definition (in my childhood), and none of these actions had anything to do with perceived injustices or the will to restore justice. There was no other intention than to harm the other person. That´s exactly why I would call them "evil". Had there been another motive or intention or abstraction that caused me to merely accept the harm these actions wouldn´t have been "evil", per your very definition.
If this is true, then all evil has an element of goodness in it, and in a real sense goodness is a main ingredient in motivating evil.
Doesn´t follow.
This goodness (justice) is twisted or misapplied, but still, without a sense of justice there could be no evil.
You use "sense of justice" and "justice" here as though they were the same. A "sense of justice" that results in "misapplied justice" isn´t "justice" - if anything, it would be "injustice". I really wouldn´t know what´s good about a "sense of justice" that causes people to commit injustices.
Plus, your first sentence violates your very definition of "evil": If the driving factor is goodness (even though misapplied) the action isn´t "evil" (as in driven by the will to do bad).