Īśvara—a controller. Kṛṣṇa is parameśvara, the supreme controller; One of the five tattvas, or Vedic ontological truths: the supreme controller of all living and nonliving energy. In Bg. 18.61-62, Lord Kṛṣṇa tells Arjuna: īśvaraḥ sarva-bhūtānāṁ hṛd-deśe 'rjuna tiṣṭhati bhrāmayan sarva-bhūtāni yantrārūḍhāni māyayā tam eva śaraṇaṁ gaccha sarva-bhāvena bhārata tat-prasādāt parāṁ śāntiṁ sthānaṁ prāpsyasi śāśvatam. The Supreme Lord (īśvara) is situated in everyone's heart, O Arjuna, and is directing the wanderings of all living entities, who are seated as on a machine, made of the material energy. O scion of Bharata, surrender unto Him utterly. By His grace you will attain transcendental peace and the supreme and eternal abode. And Cc., Ādi-līlā 5.142 states: ekale īśvara kṛṣṇa, āra saba bhṛtya yāre yaiche nācāya, se taiche kare nṛtya. Lord Kṛṣṇa alone is the supreme controller, and all others are His servants. They dance as He makes them do so. The īśvara has full control over the jīva, prakṛti, kāla and karma. The jīva has the power to choose whether to surrender to the īśvara or not. If he does surrender, he is freed from bondage within prakṛti, kāla and karma. If he does not, he is bound by them in the cycle of birth and death (saṁsāra). See Avatāra, Caitanya Mahāprabhu, Kṛṣṇa, Modes of nature, Supersoul, Tattva.