According to Mandukya Upanisad, the fourth state of consciousness is the ultimate goal. It is also often called "Thoughtless Awareness", in Sanskrit "Turiya". Turiya is silence. Silence is not absence of sound. SILENCE IS THE AWARENESS OF THE CONTENT AND ILLUMINATOR OF THE ABSENCE OF SOUND.
Thoughtless awareness is paradoxical in the sense that how can one be aware without thoughts? Vedanta (Upanisad) says that thoughtless is to be understood as destruction of impurities of the mind and not total destruction of mind.
It is brought out lucidly in the Upanishads that neither absence of thoughts is liberation (freedom) nor presence of thoughts is bondage. One should aim for fearlessness, detachment and purity of mind for enjoying the fourth state of consciousness.
Fourth state is living in the present. When one is capable of dropping all projections, memories and experiences, one experiences the fourth state. Talking or writing about Turiya is simple, but to make sure no thought enters the mind without permission (!) is a monumental task. Do you agree?