From Chogyam Trungpa
In the absence of thoughts and emotions, the Lords (the forces of materialism) bring up a still more powerful weapon, concepts. Labeling phenomena creates a feeling of a solid, definite world of "things." Such a solid world reassures us that we are a solid, continuous thing as well.
The world exists, therefore I, the perceiver of the world, exist. Meditation involves seeing the transparency of concepts, so that labeling no longer serves as a way of solidifying our world and our image of self. Labeling becomes simply the act of discrimination.