Pradyumna: "In the Padma Purāṇa also the same process is advised. There it is said that one should always remember Lord Viṣṇu. This is called dhyāna, or meditation—always remembering Kṛṣṇa. It is said that one has to meditate with his mind fixed upon Viṣṇu. Padma Purāṇa recommends that one always fix his mind on the form of Viṣṇu by meditation, and not forget Him at any moment. And this stage of consciousness is called samādhi, or trance."
Prabhupāda: Yogic mystic meditation means to concentrate the mind upon Kṛṣṇa or Viṣṇu. Dhyānāvasthita tad-gatena manasā paśyanti yaṁ yoginaḥ (SB 12.13.1). Yogī, those who are real yogīs, they always observe the Viṣṇu form within the heart. That is the process of meditation and samādhi.
Go on.
Pradyumna: "We should always try to mold the activities of our lives in such a way that we will constantly remember Viṣṇu or Kṛṣṇa. That is Kṛṣṇa consciousness. Whether one concentrates his mind on the four-handed form of Viṣṇu or on the form of two-handed Kṛṣṇa, it is the same. The Padma Purāṇa recommends you somehow or other always think of Viṣṇu, without forgetting Him, under any circumstances."
"Actually, this is the most basic of all regulative principles. For, when there is an order from a superior about doing something, there is simultaneously a prohibition. When the order is that one should always remember Kṛṣṇa, the prohibition is that one should never forget Him. Within this simple order and prohibition all regulative principles are found complete."
Prabhupāda: Smartavyaḥ satato viṣṇuḥ vismartavyaṁ na jātucit. This is . . . this is the principle of Kṛṣṇa conscious life. We should always remember Kṛṣṇa, or Viṣṇu, and we shall never forget Him. We shall mold our life in such a way . . . this Kṛṣṇa consciousness movement, International Society, on this process they are acting. They're publishing, they're going to saṅkīrtana party on the street—even they are arrested, they cannot forget Kṛṣṇa. Even they are put into the jail, there also, chanting Hare Kṛṣṇa or remembering Kṛṣṇa, that "For pushing on Kṛṣṇa consciousness movement, we have come to jail." And they are chanting; they're free to chant.
So ahaituky apratihatā: Kṛṣṇa consciousness cannot be checked in any condition of life, provided we are serious. It is so nice. Any condition, any circumstances, without any check, we can remember Kṛṣṇa. Satato smartavyaḥ . . . smartavyo viṣṇuḥ. Kīrtanīyaḥ sadā hariḥ (CC Adi 17.31). These are the instruction.