Since it is very difficult for us to think and talk about negations, we need to make a very clear distinction between the words that people use, and the internal representations that they make. When someone says, Im not cruel, they could be making images of being kind, which works fine. Or they could be making images of cruelty and then negating them, or they could be doing both.
When we think of ourselves as not having a quality that we dont like, we set a process in motion that creates a division between our conscious and unconscious minds. This becomes the foundation for an unacknowledged shadow self, a process that can ultimately lead to paranoia. The same process may also lead to multiple personality, if the shadow side is thought of as being inside the body, rather than outside. Replacing the negation with a positive representation of who we are is easy in the earlier stages of this process, but much more difficult later.
Negated representations of valued qualities can be very useful and valuable motivators, as long as we think it is possible to develop that quality at some future time. If you dont think its possible, this usually leads to envy and feelings of inferiority. Changing your belief from impossibility to possibility opens up a wide range of choices, from eager motivation to a decision that even though its possible, you dont want to put in the effort required. If we really conclude that we cant achieve a quality, it is much better to simply focus our attention on all the valued qualities that we do have. We can admire and take pleasure in the unique and exceptional qualities that others have, and dispense with useless comparisons and negated representations of ourselves.
Finally we have learned everything we need to know in order to make the most difficult and useful kind of self-concept change, transforming a quality that someone doesnt like into its desired opposite.