In the Brahma-sūtra it is said: tad-ananyatvam ārabhambhaṇa-śabdādibhyaḥ (2.1.14). This cosmic manifestation is a mixture of matter and spirit, but the cause is the Supreme Brahman, the Supreme Personality of Godhead. Therefore in Śrīmad-Bhāgavatam (1.5.20) it is said: idaṁ hi viśvaṁ bhagavān ivetaraḥ. The entire cosmic manifestation is but a transformation of the energy of the Supreme Personality of Godhead, but because of illusion, no one can appreciate that God is nondifferent from the material world. Actually He is not different, but this material world is simply a transformation of His different energies; parāsya śaktir vividhaiva śrūyate. There are also other versions of this in the Vedas: sarvaṁ khalv idaṁ brahma. Matter and spirit are all nondifferent from the Supreme Brahman, Bhagavān. Lord Śrī Kṛṣṇa confirms this statement in the Bhagavad-gītā (7.4): me bhinnā prakṛtir aṣṭadhā. The material energy is Kṛṣṇa’s energy, but it is separated from Him. The spiritual energy is also His energy, but it is not separated from Him. When the material energy is engaged in the service of the Supreme Spirit, so-called material energy is also transformed into spiritual energy, just as an iron rod becomes fire when placed in contact with fire. When we can understand by an analytical study that the Supreme Personality of Godhead is the cause of all causes, our knowledge is perfect. Simply understanding the transformations of different energies is partial knowledge. We must come to the ultimate cause. Na te viduḥ svārtha gatiṁ hi viṣṇum. The knowledge of those who are not interested in knowing the original cause of all emanations is never perfect knowledge. There is nothing in the phenomenal world that is not produced by the supreme energy of the Supreme Personality of Godhead. Aromas from the earth are different scents manufactured and used for different purposes, but the original cause is the earth, nothing else. A waterpot made of earth can be used to carry water for some time, but ultimately the pot is nothing but earth. Therefore there is no difference between the pot and its original ingredient, earth. It is simply a different transformation of the energy. Originally the cause or primary ingredient is the Supreme Personality of Godhead, and the varieties are only by-products. In the Chāndogya Upaniṣad it is stated: yathā saumy ekena mṛt-piṇḍena sarvaṁ mṛnmayaṁ vijñātaṁ syād vācārambhaṇaṁ vikāro nāmadheyaṁ mṛttikety eva satyam. If one studies the earth, he naturally understands the by-products of the earth. The Vedas therefore enjoin, yasmin vijñāte sarvam evaṁ vijñātaṁ bhavati (Muṇḍaka Upaniṣad 1.3): if one simply understands the original cause, Kṛṣṇa, the cause of all causes, then naturally everything else is understood, although it may be presented in different varieties. By understanding the original cause of different varieties, one can understand everything. If we understand Kṛṣṇa, the original cause of everything, we do not need to separately study the subsidiary varieties. Therefore from the very beginning it is said: satyaṁ paraṁ dhīmahi. One has to concentrate one’s understanding on the Supreme Truth, Kṛṣṇa or Vāsudeva. The word Vāsudeva indicates the Supreme Personality of Godhead, who is the cause of all causes. Mat-sthāni sarva-bhūtāni na cāhaṁ teṣv avasthitaḥ. This is a summary of phenomenal and noumenal philosophy. The phenomenal world depends on the noumenal existence; similarly, everything exists by virtue of the potency of the Supreme Lord, although due to our ignorance the Supreme Lord is not perceived in everything.