Krsna says that there are two kinds of nature: superior nature, or higher nature, and inferior nature. We take it for granted that there is something like inferior nature. Of course, this material energy, the material nature, is called inferior nature - inferior in the sense that matter has got no incentive. Without touch of spirit, matter cannot work. Therefore it is understood that it is inferior. But in the higher sense it is not inferior. How it is not inferior? Because it is emanation from the Supreme and you cannot separate this energy from the Supreme, and there is no difference between the Supreme and His energy.
Lecture on Bhagavad-gita 4.20-24, New York, August 9, 1966