How is idealistic evil similar to instrumental evil? How are they different?

How is idealistic evil similar to instrumental evil? How are they different? Give real-life examples of idealistic evil and instrumental evil that highlight the differences between the two.

I recently impulse-bought A Philosophy of Evil by Lars Svendsen, a Norwegian philosopher I’d never heard of. The book called out to me from the bookstore shelf, the title on the stark cover promising a brave attempt to tackle a very difficult subject head-on.

The nature of evil — along with the closely related question of the nature of good — is one of the primary unresolved questions of ethical philosophy, and has remained unresolved from the age of Plato to today.

To frame the terms “good” and “evil” in a philosophical setting is to suggest that they can be defined in some kind of meaningful, pragmatic and universal way, but few attempts to provide these definitions have ever been considered successful.