Baal HaSulam, “Introduction to The Book of Zohar,” Item 21: …for the will in any essence creates needs, and the needs create thoughts and concepts so as to obtain those needs, which the will to receive demands.
And as human desires differ from one another, so do their needs, thoughts, and ideas.
We may believe that we are very clever and that our mind encompasses all of reality, but if we are not interested in something, if it doesn’t concern us, then our mind also passes it by. It is because it is a slave. If we want something on the corporeal level, it acts to satisfy the desire relating to food, sex, or family. If a desire for respect awakens, then it is drawn to this problem and ignores other needs. It is the same when it comes to domination or money, and in general, all different combinations of our demands. A person is motivated by a combination of different desires, and the mind always operates according to the spectrum of different desires.
On the whole, we have no truly free mind. It can never be totally cold and objective, detached from feelings, as we want or think that it is. It is merely a servant of the desire.
From the 4th part of the Daily Kabbalah Lesson 1/10/14, Writings of Baal HaSulam