This verse more clearly explains the real nature of the soul, which is spread all over the body. Anyone can understand what is spread all over the body: it is consciousness. Everyone is conscious of the pains and pleasures of the body in part or as a whole. This spreading of consciousness is limited within one's own body. The pains and pleasures of one body are unknown to another. Therefore, each and every body is the embodiment of an individual soul, and the symptom of the soul's presence is perceived as individual consciousness. This soul is described as one ten-thousandth part of the upper portion of the hair point in size.
(BHAGAVAD-GITA-------2:17-------PURPORT).

The feature of the Lord by which He is present everywhere is called Paramātmā. Ātmā means the individual soul, and Paramātmā means the individual Supersoul; both ātmā and Paramātmā are individual persons. The difference between ātmā and Paramātmā is that the ātmā, or the soul, is present only in a particular body, whereas the Paramātmā is present everywhere. In this connection, the example of the sun is very nice. An individual person may be situated in one place, but the sun, even though a similar individual entity, is present on the head of every individual person. In Bhagavad-gītā this is explained. Therefore even though the qualities of all entities, including the Lord, are equal, the Supersoul is different from the individual soul by quantitative power of expansion. The Lord, or the Supersoul, can expand Himself into millions of different forms, whereas the individual soul cannot do so.
(SRIMAD BHAGAVATAM------3:15:45------PURPORT).

Therefore, the individual particle of spirit soul is a spiritual atom smaller than the material atoms, and such atoms are innumerable. This very small spiritual spark is the basic principle of the material body, and the influence of such a spiritual spark is spread all over the body as the influence of the active principle of some medicine spreads throughout the body. This current of the spirit soul is felt all over the body as consciousness, and that is the proof of the presence of the soul. Any layman can understand that the material body minus consciousness is a dead body, and this consciousness cannot be revived in the body by any means of material administration. Therefore, consciousness is not due to any amount of material combination, but to the spirit soul.
(BHAGAVAD-GITA-------2:17-------PURPORT).

It is stated in Bhagavad-gītā that a person who is always absorbed in Kṛṣṇa consciousness is the topmost yogī. What is Kṛṣṇa consciousness? As the individual soul is present by his consciousness throughout his entire body, so the Supersoul, or Paramātmā, is present throughout the whole creation by superconsciousness. This superconscious energy is imitated by the individual soul, who has limited consciousness. I can understand what is going on within my limited body, but I cannot feel what is going on in another's body. I am present throughout my body by my consciousness, but my consciousness is not present in another's body. The Supersoul, or Paramātmā, however, being present everywhere and within everyone, is also conscious of everyone's existence. The theory that the soul and the Supersoul are one is not acceptable because it is not confirmed by authoritative Vedic literature. The individual soul's consciousness cannot act in superconsciousness. This superconsciousness can be achieved, however, by dovetailing individual consciousness with the consciousness of the Supreme. This dovetailing process is called surrender, or Kṛṣṇa consciousness.
(SRIMAD BHAGAVATAM------3:15:45------PURPORT).

The soul does not take birth there, and the soul does not die. Anything which has birth also has death. And because the soul has no birth, he therefore has no past, present or future. He is eternal, ever-existing, and primeval—that is, there is no trace in history of his coming into being. Under the impression of the body, we seek the history of birth, etc., of the soul. The soul does not at any time become old, as the body does. The so-called old man, therefore, feels himself to be in the same spirit as in his childhood or youth. The changes of the body do not affect the soul. The soul does not deteriorate like a tree, nor anything material. The soul has no by-product either. The by-products of the body, namely children, are also different individual souls; and, owing to the body, they appear as children of a particular man. The body develops because of the soul's presence, but the soul has neither offshoots nor change. Therefore, the soul is free from the six changes of the body.
(BHAGAVAD-GITA-------2:20-------PURPORT).

A person who is freed from material designations can see the same quality of spirit present everywhere or in every manifested living entity. Less intelligent men think that plants and grass grow out of the earth automatically, but one who is actually intelligent and has realized the self can see that this growth is not automatic; the cause is the soul, and the forms come out in material bodies under different conditions. By fermentation in the laboratory many germs are born, but this is due to the presence of the soul. The material scientist thinks that eggs are lifeless, but that is not a fact. From Vedic scripture we can understand that living entities in different forms are generated under different conditions. Birds evolve from eggs, and beasts and human beings are born from the embryo. The perfect vision of the yogī or devotee is that he sees the presence of the living entity everywhere.
(SRIMAD BHAGAVATAM------3:28:42------PURPORT).

The soul is full of knowledge, or full always with consciousness. Therefore, consciousness is the symptom of the soul. Even if one does not find the soul within the heart, where he is situated, one can still understand the presence of the soul simply by the presence of consciousness. Sometimes we do not find the sun in the sky owing to clouds, or for some other reason, but the light of the sun is always there, and we are convinced that it is therefore daytime. As soon as there is a little light in the sky early in the morning, we can understand that the sun is in the sky. Similarly, since there is some consciousness in all bodies—whether man or animal—we can understand the presence of the soul. This consciousness of the soul is, however, different from the consciousness of the Supreme because the supreme consciousness is all-knowledge—past, present and future. The consciousness of the individual soul is prone to be forgetful. When he is forgetful of his real nature, he obtains education and enlightenment from the superior lessons of Kṛṣṇa. But Kṛṣṇa is not like the forgetful soul. If so, Kṛṣṇa's teachings of Bhagavad-gītā would be useless.
(BHAGAVAD-GITA-------2:20-------PURPORT).

The Supreme Lord, as Supersoul, is always present with the individual soul. He directs material nature to supply a particular type of body to the individual soul according to the result of his work, and the material nature supplies it. Here one word, retaḥ-kaṇāśrayaḥ, is very significant because it indicates that it is not the semen of the man that creates life within the womb of a woman; rather, the living entity, the soul, takes shelter in a particle of semen and is then pushed into the womb of a woman. Then the body develops. There is no possibility of creating a living entity without the presence of the soul simply by sexual intercourse. The materialistic theory that there is no soul and that a child is born simply by material combination of the sperm and ovum is not very feasible. It is unacceptable.
(SRIMAD BHAGAVATAM------3:31:1------PURPORT).

As far as the bodies are concerned in different castes or different species of life, the Lord is equally kind to everyone because He treats every living being as a friend yet maintains Himself as Paramātmā regardless of the circumstances of the living entities. The Lord as Paramātmā is present both in the outcaste and in the brāhmaṇa, although the body of a brāhmaṇa and that of an outcaste are not the same. The bodies are material productions of different modes of material nature, but the soul and the Supersoul within the body are of the same spiritual quality. The similarity in the quality of the soul and the Supersoul, however, does not make them equal in quantity, for the individual soul is present only in that particular body whereas the Paramātmā is present in each and every body. A Kṛṣṇa conscious person has full knowledge of this, and therefore he is truly learned and has equal vision. The similar characteristics of the soul and Supersoul are that they are both conscious, eternal and blissful. But the difference is that the individual soul is conscious within the limited jurisdiction of the body whereas the Supersoul is conscious of all bodies. The Supersoul is present in all bodies without distinction.
(BHAGAVAD-GITA-------5:18-------PURPORT).

Everyone knows that his material body has developed from a spiritual spark, and similarly the universal body has developed from the supreme spark, Supersoul. As the individual body develops from the individual soul, the gigantic body of the universe develops from the Supreme Soul. Just as the individual soul has consciousness, the Supreme Soul is also conscious. But although there is a similarity between the consciousness of the Supreme Soul and the consciousness of the individual soul, the individual soul's consciousness is limited, whereas the consciousness of the Supreme Soul is unlimited. This is described in Bhagavad-gītā (13.3). Kṣetra-jñaṁ cāpi māṁ viddhi: the Supersoul is present in every field of activity, just as the individual soul is present in the individual body. Both of them are conscious. The difference is that the individual soul is conscious of the individual body only, whereas the Supersoul is conscious of the total number of individual bodies.
(SRIMAD BHAGAVATAM------3:32:29------PURPORT).

Everything that exists is a product of matter and spirit. Spirit is the basic field of creation, and matter is created by spirit. Spirit is not created at a certain stage of material development. Rather, this material world is manifested only on the basis of spiritual energy. This material body is developed because spirit is present within matter; a child grows gradually to boyhood and then to manhood because that superior energy, spirit soul, is present. Similarly, the entire cosmic manifestation of the gigantic universe is developed because of the presence of the Supersoul, Viṣṇu. Therefore spirit and matter, which combine to manifest this gigantic universal form, are originally two energies of the Lord, and consequently the Lord is the original cause of everything. A fragmental part and parcel of the Lord, namely the living entity, may be the cause of a big skyscraper, a big factory, or even a big city, but he cannot be the cause of a big universe. The cause of the big universe is the big soul, or the Supersoul. And Kṛṣṇa, the Supreme, is the cause of both the big and small souls. Therefore He is the original cause of all causes. This is confirmed in the Kaṭha Upaniṣad (2.2.13). Nityo nityānāṁ cetanaś cetanānām.
(BHAGAVAD-GITA-------7:6-------PURPORT).

The body is taken to be the field, and the individual soul is taken to be the worker in that field. Yet there is another, who is known as the Supersoul, who, along with the individual soul, simply witnesses. The individual soul works and enjoys the fruits of the body, whereas the Supersoul simply witnesses the activities of the individual soul but does not enjoy the fruits of those activities. The Supersoul is present in every field of activity, whereas the individual soul is present in his one localized body. King Malayadhvaja attained this perfection of knowledge and was able to distinguish between the soul and the Supersoul and the soul and the material body.
(SRIMAD BHAGAVATAM------4:28:40------PURPORT).

Those who do not directly worship the Supreme Godhead, Kṛṣṇa, but who attempt to achieve the same goal by an indirect process, also ultimately achieve the same goal, Śrī Kṛṣṇa. "After many births the man of wisdom seeks refuge in Me, knowing that Vāsudeva is all." When a person comes to full knowledge after many births, he surrenders unto Lord Kṛṣṇa. If one approaches the Godhead by the method mentioned in this verse, he has to control the senses, render service to everyone and engage in the welfare of all beings. It is inferred that one has to approach Lord Kṛṣṇa, otherwise there is no perfect realization. Often there is much penance involved before one fully surrenders unto Him.
In order to perceive the Supersoul within the individual soul, one has to cease the sensual activities of seeing, hearing, tasting, working, etc. Then one comes to understand that the Supreme Soul is present everywhere. Realizing this, one envies no living entity—he sees no difference between man and animal because he sees soul only, not the outer covering. But for the common man, this method of impersonal realization is very difficult.

(BHAGAVAD-GITA-------12:3-4-------PURPORT).

There are various theories regarding consciousness. Here in Bhagavad-gītā the example of the sun and the sunshine is given. As the sun is situated in one place but is illuminating the whole universe, so a small particle of spirit soul, although situated in the heart of this body, is illuminating the whole body by consciousness. Thus consciousness is the proof of the presence of the soul, as sunshine or light is the proof of the presence of the sun. When the soul is present in the body, there is consciousness all over the body, and as soon as the soul has passed from the body there is no more consciousness. This can be easily understood by any intelligent man. Therefore consciousness is not a product of the combinations of matter. It is the symptom of the living entity.

(BHAGAVAD-GITA-------13:34-------PURPORT).

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