This is a quote taken from Jeffrey Brooks book, Rhinoceros Zen: Zen Martial Arts and the Path to Freedom:
In karate practice every move you make must be made with
intention. You can’t just reposition your body in the air, adopt the
posture of a punch or a block and think you are really training
karate. In karate your intention itself is what you are training.
A kata is a sequence of fighting moves performed against a series
of imaginary opponents. It is one of the two primary methods for
training in the traditional martial arts—not only on Okinawa, but in
China and Japan as well. If kata is trained without intention in the
movements it will not be useful for self- defense. If you are training
your intention, not just your posture, it is an effective means of
perfecting fighting skills.