The influence of the atomic soul can be spread all over a particular body. According to the Muṇḍaka Upaniṣad, this atomic soul is situated in the heart of every living entity, and because the measurement of the atomic soul is beyond the power of appreciation of the material scientists, some of them assert foolishly that there is no soul. The individual atomic soul is definitely there in the heart along with the Supersoul, and thus all the energies of bodily movement are emanating from this part of the body. The corpuscles which carry the oxygen from the lungs gather energy from the soul. When the soul passes away from this position, the activity of the blood, generating fusion, ceases. Medical science accepts the importance of the red corpuscles, but it cannot ascertain that the source of the energy is the soul. Medical science, however, does admit that the heart is the seat of all energies of the body.
Such atomic particles of the spirit whole are compared to the sunshine molecules. In the sunshine there are innumerable radiant molecules. Similarly, the fragmental parts of the Supreme Lord are atomic sparks of the rays of the Supreme Lord, called by the name prabhā, or superior energy. So whether one follows Vedic knowledge or modern science, one cannot deny the existence of the spirit soul in the body, and the science of the soul is explicitly described in the Bhagavad-gītā by the Personality of Godhead Himself.

(BHAGAVAD-GITA------2:17-------PURPORT).

Everyone is working hard day and night just to give pleasure to his own self, under either the bodily or spiritual concept of life. We are attached to material possessions because they give pleasure to the senses or to the body. The attachment to the body is there only because the "I," the spirit soul, is within the body. Similarly, when one is further advanced, he knows that the spirit soul is pleasing because it is part and parcel of Kṛṣṇa. Ultimately, it is Kṛṣṇa who is pleasing and all-attractive. He is the Supersoul of everything. And in order to give us this information, Kṛṣṇa descends and tells us that the all-attractive center is He Himself. Without being an expansion of Kṛṣṇa, nothing can be attractive.

(KRSNA BOOK).

Just with a little contemplation he can come to understand that the body is his possession. One can understand this by practical experience and by the authority of the śāstras. In Bhagavad-gītā (2.13) it is said: dehino'smin yathā dehe. The proprietor of the body, the soul, is within the body. The body is taken as the pañcāla-deśa, or the field of activities wherein the living entity can enjoy the senses in their relationship to the five sense objects, namely gandha, rasa, rūpa, sparśa and śabda—that is, sense objects made out of earth, water, fire, air and sky. Within this material world, covered by the material body of subtle and gross matter, every living entity creates actions and reactions, which are herein known allegorically as sons and grandsons. There are two kinds of actions and reactions—namely pious and impious. In this way our material existence becomes coated by different actions and reactions.

(SRIMAD BHAGAVATAM------4:27:9-------PURPORT).

This statement by the brāhmaṇa is very instructive. It is a fact that the Supreme Lord, the Personality of Godhead, in His Paramātmā feature, enters the creation of this material world as Mahā-Viṣṇu, Garbhodakaśāyī Viṣṇu and Kṣīrodakaśāyī Viṣṇu, and in a very friendly attitude the Lord sits along with the conditioned soul in the body. Therefore, every living entity has the Lord with him from the very beginning, but due to his mistaken consciousness of life, the living entity cannot understand this. When his consciousness, however, is changed into Kṛṣṇa consciousness, he can immediately understand how Kṛṣṇa is trying to assist the conditioned souls to get out of the material entanglement.

(KRSNA BOOK).

They think that the control behind this gigantic manifestation is imagination. Intelligent persons, however, can estimate the value of the cause by observing the wonders of the effects. For example, the individual human body does not develop from the womb of the mother independently but because the living entity, the soul, is within the body. Without the living entity, a material body cannot automatically take shape or develop. When any material object displays development, it must be understood that there is a spiritual soul within the manifestation. The gigantic universe has developed gradually, just as the body of a child develops. The conception that the Transcendence enters within the universe is, therefore, logical.

(SRIMAD BHAGAVATAM------3:6:10-------PURPORT).

The Māyāvādī philosophers' thesis that God and the individual soul are one and the same cannot be accepted because the individual soul has to develop his power according to the development of different types of bodies. The individual soul in the body of a baby cannot show the full power of a grown man, but the Supreme Personality of Godhead, Kṛṣṇa, even when lying on the lap of His mother as a baby, could exhibit His full power by killing Pūtanā and other demons who attacked Him. Thus the spiritual potency of the Supreme Personality of Godhead is said to be eka-rasa, or without change. The Supreme Personality of Godhead, therefore, is the only worshipable object, and this is perfectly known to persons who are uncontaminated by the modes of material nature.

(KRSNA BOOK).

The fact that the atomic soul is within the body of a gigantic animal, in the body of a gigantic banyan tree, and also in the microbic germs, millions and billions of which occupy only an inch of space, is certainly very amazing. Men with a poor fund of knowledge and men who are not austere cannot understand the wonders of the individual atomic spark of spirit, even though it is explained by the greatest authority of knowledge, who imparted lessons even to Brahmā, the first living being in the universe. Owing to a gross material conception of things, most men in this age cannot imagine how such a small particle can become both so great and so small. So men look at the soul proper as wonderful either by constitution or by description.

(BHAGAVAD-GITA------2:29-------PURPORT).

Such persons eat all kinds of obnoxious things, such as meat, and take pleasure in alcohol and other intoxicants, and after death they are forced to take birth in lower species of life. Materialistic persons generally worship the transient material body and forget the welfare of the spirit soul within the body. Some take shelter of materialistic science to improve bodily comforts, and some take to the worship of demigods to be promoted to the heavenly planets. Their goal in life is to make the material body comfortable, but they forget the interest of the spirit soul. Such persons are described in the Vedic literature as suicidal, because attachment for the material body and its comforts forces the living entity to wander through the process of birth and death perpetually and suffer the material pangs as a matter of course. The human form of life is a chance for one to understand his position.

(KRSNA BOOK).

They think that the control behind this gigantic manifestation is imagination. Intelligent persons, however, can estimate the value of the cause by observing the wonders of the effects. For example, the individual human body does not develop from the womb of the mother independently but because the living entity, the soul, is within the body. Without the living entity, a material body cannot automatically take shape or develop. When any material object displays development, it must be understood that there is a spiritual soul within the manifestation. The gigantic universe has developed gradually, just as the body of a child develops. The conception that the Transcendence enters within the universe is, therefore, logical.

(SRIMAD BHAGAVATAM------3:6:10-------PURPORT).

The fact that the atomic soul is within the body of a gigantic animal, in the body of a gigantic banyan tree, and also in the microbic germs, millions and billions of which occupy only an inch of space, is certainly very amazing. Men with a poor fund of knowledge and men who are not austere cannot understand the wonders of the individual atomic spark of spirit, even though it is explained by the greatest authority of knowledge, who imparted lessons even to Brahmā, the first living being in the universe. Owing to a gross material conception of things, most men in this age cannot imagine how such a small particle can become both so great and so small. So men look at the soul proper as wonderful either by constitution or by description. Illusioned by the material energy, people are so engrossed in subject matters for sense gratification that they have very little time to understand the question of self-understanding, even though it is a fact that without this self-understanding all activities result in ultimate defeat in the struggle for existence. Perhaps they have no idea that one must think of the soul, and thus make a solution to the material miseries.

(BHAGAVAD-GITA------2:29-------PURPORT).

As stated in Bhagavad-gītā, intelligence and forgetfulness are both supplied by the Supersoul sitting with the individual soul within the body. When He sees that a conditioned soul is very serious about getting out of the clutches of the material influence, the Supreme Lord gives intelligence internally as Supersoul and externally as the spiritual master, or, as an incarnation of the Personality of Godhead Himself, He helps by speaking instructions such as Bhagavad-gītā. The Lord is always seeking the opportunity to reclaim the fallen souls to His abode, the kingdom of God. We should always feel very much obliged to the Personality of Godhead, for He is always anxious to bring us into the happy condition of eternal life. There is no sufficient means to repay the Personality of Godhead for His act of benediction; therefore, we can simply feel gratitude and pray to the Lord with folded hands.

(BHAGAVAD-GITA------3:31:18-------PURPORT).

He is directing from within and from without. From within He is directing as caitya-guru, or the spiritual master sitting within the heart. Indirectly He is also helping the living entity by manifesting Himself as the spiritual master outside. In both ways the Lord is giving directions to the living entity so that he may finish up his material activities and come back home, back to Godhead. The presence of the Supreme Soul and the individual soul within the body can be perceived by anyone by the fact that as long as the individual soul and the Supersoul are both living within the body, the body is always shining and fresh. But as soon as the Supersoul and the individual soul give up possession of the gross body, it immediately decomposes.
(SRIMAD BHAGAVATAM------4:22:37-------PURPORT).

The word adhiṣṭhānam refers to the body. The soul within the body is acting to bring about the results of activity and is therefore known as kartā, "the doer." That the soul is the knower and the doer is stated in the śruti. Eṣa hi draṣṭā sraṣṭā (Praśna Upaniṣad 4.9). It is also confirmed in the Vedānta-sūtra by the verses jño 'ta eva (2.3.18) and kartā śāstrārthavattvāt (2.3.33). The instruments of action are the senses, and by the senses the soul acts in various ways. For each and every action there is a different endeavor. But all one's activities depend on the will of the Supersoul, who is seated within the heart as a friend. The Supreme Lord is the supercause. Under these circumstances, he who is acting in Kṛṣṇa consciousness under the direction of the Supersoul situated within the heart is naturally not bound by any activity.

(BHAGAVAD-GITA------2:29-------PURPORT).

When one actually becomes spiritually advanced, he does not see the difference between one living entity and another. This platform is attained by determination. When perfect knowledge is expanded, one ceases to see the outward covering of the living entity. He sees, rather, the spirit soul within the body. Thus he does not make distinctions between a human being and an animal, a learned brāhmaṇa and a caṇḍāla.

(SRIMAD BHAGAVATAM------4:31:2-------PURPORT).

Just with a little contemplation he can come to understand that the body is his possession. One can understand this by practical experience and by the authority of the śāstras. In Bhagavad-gītā (2.13) it is said: dehino'smin yathā dehe. The proprietor of the body, the soul, is within the body. The body is taken as the pañcāla-deśa, or the field of activities wherein the living entity can enjoy the senses in their relationship to the five sense objects, namely gandha, rasa, rūpa, sparśa and śabda—that is, sense objects made out of earth, water, fire, air and sky. Within this material world, covered by the material body of subtle and gross matter, every living entity creates actions and reactions, which are herein known allegorically as sons and grandsons. There are two kinds of actions and reactions—namely pious and impious.

(SRIMAD BHAGAVATAM------4:27:9-------PURPORT).

This is confirmed in Bhagavad-gītā (2.18). Antavanta ime dehā nityasyoktāḥ śarīriṇaḥ: the body is perishable, but the soul within the body is imperishable. Therefore the duty of those advanced in knowledge in human society is to study the constitutional position of the imperishable soul and not waste the valuable time of human life in merely maintaining the body and not considering life's real responsibility. Every human being should try to understand how the spirit soul can be happy and where he can attain an eternal, blissful life of knowledge. Human beings are meant to study these subject matters, not to be absorbed in caring for the temporary body, which is sure to change.

(SRIMAD BHAGAVATAM------7:2:58-------PURPORT).

The purport is that as long as we are in this human form of body, our duty is to understand the soul within the body. The body is not the self; we are different from the body, and therefore there is no question of friends, enemies or responsibilities in terms of the bodily conception of life. One should not be very anxious about the body's changing from childhood to boyhood, from boyhood to old age and then to apparent annihilation. Rather, one should be very seriously concerned about the soul within the body and how to release the soul from the material clutches.

(SRIMAD BHAGAVATAM------7:2:60-------PURPORT).

One who understands this truth should not be very much anxious about the maintenance of his body. There is no possibility of maintaining the body permanently or eternally. Antavanta ime dehā nityasyoktāḥ śarīriṇaḥ. This is the statement of Bhagavad-gītā (2.18). The material body is antavat (perishable), but the soul within the body is eternal (nityasyoktāḥ śarīriṇaḥ). Lord Viṣṇu and the individual souls, who are part and parcel of Him, are both eternal. Nityo nityānāṁ cetanaś cetanānām (Kaṭha Upaniṣad 2.2.13). Lord Viṣṇu is the chief living being, whereas the individual living entities are parts of Lord Viṣṇu. All the various grades of bodies—from the gigantic universal body to the small body of an ant—are perishable, but the Supersoul and the soul, being equal in quality, both exist eternally.

(SRIMAD BHAGAVATAM------7:7:18-------PURPORT).

Here is a very good example concerning spiritual understanding. Foolish rascals, including so-called jñānīs, philosophers and scientists, cannot understand the existence of the soul within the body because they are lacking in spiritual knowledge. The Vedas enjoin, tad-vijñānārthaṁ sa gurum evābhigacchet: (MU 1.2.12) to understand spiritual knowledge, one must approach a bona fide spiritual master. Unless one has been trained in geology, one cannot detect gold in stone. Similarly, unless one has been trained by a spiritual master, he cannot understand what is spirit and what is matter. Here it is said, yogais tad-abhijñaḥ. This indicates that one who has connected himself with spiritual knowledge can understand that there is a spiritual soul within the body.

(SRIMAD BHAGAVATAM------7:7:21-------PURPORT).

One who has not been trained cannot distinguish between gold and stone. Similarly, fools and rascals who have not learned from an expert spiritual master what is soul and what is matter cannot understand the existence of the soul within the body. To understand such knowledge, one must be trained in the mystic yoga system, or, finally, in the bhakti-yoga system. As stated in Bhagavad-gītā (18.55), bhaktyā mām abhijānāti. Unless one takes shelter of the bhakti-yoga process, one cannot understand the existence of the soul within the body.

(SRIMAD BHAGAVATAM------7:7:21-------PURPORT).

Thus he can understand that the head, hands, legs and indeed the entire body have grown on the basis of the soul. If the soul is within, the body, head, hands and legs grow, but otherwise they do not. A dead child does not grow up, for the soul is not present. If by a careful analysis of the body one still cannot find the existence of the soul, this is due to his ignorance. How can a gross man fully engaged in materialistic activities understand the soul, which is a small particle of spirit one ten-thousandth the size of the tip of a hair? Such a person foolishly thinks that the material body has grown from a combination of chemicals, although he cannot find them.

(SRIMAD BHAGAVATAM------7:7:24-------PURPORT).

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