Answer: There are positive thoughts aimed at connection and good for others. There are negative thoughts aimed at separation, at the submission of others to ourselves. They are all graduated on levels.
In the spiritual worlds, there are 125 steps of good or evil thoughts; along with positive thoughts, there is a great system of dark forces, evil thoughts, which are described in The Book of Zohar. But as a system, we do not study it.
Kabbalists saw that when you study a system of wrong, evil thoughts, at the same time, you awaken them and it does not act well on us and the whole world. Therefore, we do not study that. It is described by Kabbalists, but we do not include it in our course of study.
If we become so big that we can use this system only for our benefit, then we will study it.
From the Kabbalah Lesson in Russian 2/3/19