So too, friend, purification of virtue is for the sake of reaching purification of mind; purification of mind is for the sake of reaching purification of view; purification of view is for the sake of reaching purification by overcoming doubt; purification by overcoming doubt is for the sake of reaching purification by knowledge and vision of what is the path and what is not the path; purification by knowledge and vision of what is the path and what is not the path is for the sake of reaching purification by knowledge and vision of the way; purification by knowledge and vision of the way is for the sake of reaching purification by knowledge and vision; purification by knowledge and vision is for the sake of reaching final Nibbāna [Nirvana] without clinging. It is for the sake of final Nibbāna without clinging that the holy life is lived under the Blessed One.
Gautama Buddha, The Middle Length Discourses of the Buddha: A Translation of the Majjhima Nikaya
buddhism, path, rathavinīta, sutra