Philosophy means metaphysical realization of the essence of Truth. Since soul is the essence of all that is living, he who knows the soul, knows all. Philosophy rests on the foundation of realization and logically speaking it uses intelligence to arrive at a conclusion. Philosophy is the science of fundamental concepts, which requires help from logic and intelligence of the thinker. Philosophy is a quest in areas beyond the knowledge and is realization of the quintessence of that knowledge. Philosophy uses logical formulations, while it deals with subjects like soul, God and cycle of birth etc. Through critical analysis it tries to formulate its concepts.
There appears to be a great divergence in views on the questions like existence of the soul, re-birth etc. Philosophers of the Orient as also the Occident have contemplated a lot on these questions. Three views have come forth:
(1) there is soul and re-birth
(2) soul and God exist but no question of re-birth
(3) soul does exist, but no proof to accept God and rebirth.
The Jain Philosophy accepts the existence of the soul which takes numerous different forms. It holds that soul is eternal. Christianity and others hold a slightly different view. They accept soul and the God and yet do not believe in re-birth. The third group led by the 'Cārvāk' philosophy and others concedes that there is a thing like soul, but it is not eternal. According to them, the body itself is the soul. There is no cycle of births for the soul and that there is no God.
Even if one accepts the existence of soul, the question remains—where from it has come into existence? What was it, before its existence now? Even if one accepts that there is something like the soul which has eternal existence, the next question crops up - from where has the jīva arrived in this birth, what was it before? On this Mahāvīra said that all the jīvas do not possess the same amount of capacity to know about their previous life. Most of them do not possess intuition about the direction from which they have come to the present life. These two concepts viz., 'intuition' and 'direction' must be understood correctly. The former is derived out of memory (smriti). It also means feeling. In Ācārāṅga Niryukti, Bhāva Sanjñāna is mentioned to be of two types—(1) Jñana Sanjñā (knowledge through intellect) and (2) Anubhāva sanjñā i.e. feelings which are based on the realization of the effects of one's own karma after it reaches the fruition stage.
Lord Mahāvīra said that although the nature of the soul is re-incarnative, yet many people do not know who were they in their last birth or who they are going to be in their next birth. In this context, some of the explorations of modern science are very valuable. According to science, there are three states of matter - solid, liquid and gas. Two more were added later—plasma and protoplasm or bio-plasma, which is known in Indian philosophical terminology as 'Prāṇa Śakti'. A Soviet physicist, Mr. V. C. Grishchecov, has found that there are independent electrons and protons in the bio-plasma, having no connection with the nucleus. They have tremendous speed and have the power to intercept their message into other living beings. This is some thing like telepathy. This force is condensed in the spinal cord of the human beings. It has the power to interpret its message into other living beings.
After the intensive research on this subject, the Soviet scientists have reached some conclusions. They are as under—
(1) The basic source or seed of plasma is in the mind where it is stored in high density.(2) Bio-plasma is mostly operational in the spinal cord and in the neurons.
(3) It is concentrated more in the various nervous centres of the body.
This proves the real existence of bio-plasma, which is quite similar to the concept of the 'subtle body' as mentioned in the Indian Philosophy.
Protoplasm is immortal, but the body is mortal. (After death, the protoplasm does not perish). When we breathe, the protoplasm enters the body and through its property of nucleus it gives energy to the body. When the nucleus and its carrier agent protoplasm are weakened, we loose Cetanā (our living force).
After death this protoplasm leaves the body and gets merged into the environment. It then travels further through vegetation and finally enters new bodies through nutrition. It finally transforms itself into DNA and gets a new life through birth.
This nearly proves that 'Re-birth' is a possibility as is indicated by the results of the scientific analysis. Dr. W. J. Killer, a well-known physician in London, has carried out many experiments on the patients on their death-bed. He has documented in his book "The Human Atmosphere" that there is something like a cluster of light which remains intact even after the clinical death of the body.
The Soviet scientists have now endorsed the philosophical doctrine of 'Re-birth' (or Re-incarnation) or the cycle of births. They assert with certainty, "There exists a subtle energy or an invisible body in the form of a cluster of light, which covers the physical body in all living beings. We have obtained a proof for that." Such a cluster of light was observed through an electron microscope. Through it, they saw something as a discharge from the dying living being, which was seen only by clairvoyants earlier. Even in the living body, they could see the reflection of the same type of light. The same reflection gets absorbed into the electromagnetic fields: such is special structure of the invisible body. However, it is not exactly the philosophical soul, which is certainly a much subtler concept that what is conveyed by the 'sukṣma śarīra' (the subtle body). Let us compare and contrast the concept of protoplasm with that of the subtle body. Both the subtle body as well as protoplasm do not perish—the former takes the rebirth, the latter gets changed into 'genes' in the new body. The subtle body is neither liquid, nor gas, nor solid.
Protoplasm is also neither of the three. The subtle body is not visible to eyes. So also is the protoplasm which is observed only through microscope. The subtle body is perceived by a clairvoyant or a person having extra-sensory-perception. Thus, protoplasm is not the soul, but akin to the subtle body. Experiments in this field are continuing. The scientists are yet to reach the stage when they can explain 'soul' in precise scientific terms.
Lord Mahavira has said that in order to know about your earlier births, they are three means—the first is that you have to sharpen your smṛti (memory). The second is that you may ask others who have attained extra-sensory perception. The third is that you may know your birth through a third person who has known about it from a direct perceiver.
'Smriti' is stored in the 'sukṣma śarīra'. When it is awakened, we call it 'jāti smṛti'. The bio-sciences as also the para-psychology have found that when the protoplasm is activated in a child's brain, it may start awakening his memory of the earlier births. The Jain philosophy has found that it is the awakening of the memory stored in the subtle body, through which one could recall his previous births. It is realized through concentration and purification of 'citta' (psyche) by means of 'īha' (speculation), 'apoha' (reflection), 'margaṇā' (investigation) and 'gaveaṇā' (search). Deep contemplation or sometimes even accidental injury may activate this faculty.
Lord Mahāvīra has described the soul as—"I have come to the present life from a particular direction. What I am today is a continuation of many births and re-births 'So (a) haṃ' (which means T am that') is thus the realization of the eternal existence of the soul travelling through various births and forms." According to the Jain philosophy, each one of us is a distinct soul which carries forward to his next birth its own tejaśa śarīra or the bio-electrical body (subtle body) and the kārmaṇa body (the subltemost body); both of them are eternal. Since they never die, they continuously carry on their journey along with the soul. Thus, it can be said that the concept of protoplasm supports the philosophical truth of rebirth.
The sum total of the exposition as mentioned above could be summarized as under:
Ātmā (soul) is 'traikālika' i.e., eternal. It is set in cyclic formation with earlier birth and rebirth. The protoplasm or the subtle body always accompanies the worldly soul. It is believed by the Jain philosophy that although that is not the soul itself, yet it is the subtle body that is the primary cause of new birth or the cycle of rebirth.