Life means action; and so there is action when a soul is born. Then, as the soul continues to live, it must associate itself with action all the time. Action arises out of desire, and is followed by a result; and so there are impressions produced by actions, which are followed by other actions. Hence, these impressions of actions may be said to be the cause of other actions.
As the soul has to associate itself with actions, it must also associate itself with the impressions of these actions.
The soul is said to be without a body; but that is so only in its real essence, when it makes itself free. So long as it is associated with action, it remains encased in what may be called a "subtle body", which is composed of seventeen parts, the intellect, mind, and the essence of the ten senses, and five properties of the great "elements". It is this "subtle body" that contains a record of the experiences of the soul, the impressions of actions with which it has associated itself; and so it is by means of it that further actions take place.
As we have to agree that the same soul is born again and again, we must also agree that this "subtle body" accompanies the soul even after death, and cannot be destroyed so long as the soul is born; for it is the cause of its future actions in the world; and it is by its means that it can acquire more and more knowledge or experience of Nature, whereby it can attain to perfection and become free. The soul accordingly commences its journey of life at the stage where it leaves it at the time of previous "death"; and this continues till it acquires all knowledge or experience, becomes perfect, and is made free.
Now the question is how can the soul, passing through this series of births, attain to final freedom in the end? This, the Sankhya tells us, is possible only when it acquires perfect knowledge of all that is in Nature or Prakrti. But Prakrti is an intelligent power, for its first form of life is Mahat or Intellect. It also acts, for it is the creator of ahankara or the I-as-an-actor. At the same time it is characterized by goodness too, for it is the creator of the Mind, which has desire for its attribute, and there is an element of goodness inherent in all desire so far as the doer of the deed himself is concerned. The action of Prakrti is, accordingly, intelligent, and is designed to do good, primarily to itself, and then to the soul.
According to the Sankhya the object of the soul is to acquire perfect knowledge of all that is in Nature or Prakrti; but this is possible only if Prakrti, which is both intelligent and good, is willing to impart this knowledge to the soul; for the soul has no means of compelling it to do so. Indeed, the instruments of intellect, mind, and the senses, by means of which the soul may be said to acquire this knowledge, are all a creation of Prakrti, and so subject to its control; and so it is necessary that Prakrti itself should help the soul to acquire knowledge of itself, and make it free. It may, therefore, be said to have an affection for the soul, by means of which it attracts it for the first time, and again and again when it is re-born; but finally makes it free.
All action begins with desire, and ends when it is satisfied; and when there is no further desire, there can be no further action. Thus, when Prakrti has manifested all that it has to the soul, it has nothing more to show, and all its action towards the soul comes to an end. Similarly, when all desire of the soul to know more and more of Prakrti is satisfied, it has nothing more to desire, and no further purpose in action. In this manner all mutual attraction and action and inter-action between Prakrti and the soul comes to an end, and the soul becomes for ever free.
But this process is gradual. As more and more of knowledge means less and less of action, the soul associates itself with less and less of new actions during the latter part of its series of births; and in this manner the impressions of previous actions recorded on its "subtle body" become fainter and fainter, till at last it comes to a stage when it is born for the last time, and associates itself with the least action. There are no new impressions of actions, and the old impressions made on its "subtle body" have all died away; and so now the soul is pure soul in itself, and becomes for ever free, never again to be drawn into the tangles of Prakrti.
A criticism: This, in brief, is the main idea of the Sankhya in regard to the character of the soul, and the manner of its attaining to freedom. But it contains a number of points which lend themselves to a sharp difference of opinion; and so it is small wonder that the remaining systems have apparently conflicting points of view. For instance, we find that the Nyaya idea of the soul is very, vague; but the Vaiseshika goes to the other extreme, and conceives of as a substance, characterized by both desire and action, and no more eternal or non-eternal than the "element" Air; and, consistently with this idea, it maintains that freedom from the bondage of life can be attained not by means of renunciation of action, but by means of action performed in accordance with the highest nature of the soul. The Mimansa and Yoga take us a step or two further, but the idea is still confused; and it is only when we come to Vedanta that we find that the soul, being inseparable from its "subtle body", cannot be regarded as altogether different from all that is in Prakrti. Again, we find that knowledge itself may be regarded as a form of action; and so knowledge and action may be said to be but counterparts of the same energy of the soul; and, as the latter has prana or vital breath for its vehicle, we may be said to know as well as to act with each breath that we draw. Finally, we see that the very idea of freedom of the soul, as propounded by the Sankhya, and the manner in which it is said to be achieved, is an impossible one; for it depends on the possibility of a total elimination of the impressions of all previous actions recorded on the "subtle body".
This is inconceivable, for, though they might be made fainter and fainter, they can never be annihilated; for the last birth, whenever it takes place, being a form of action, must leave an impression on the "subtle body" of the soul, and result in a future birth again. Indeed, it is as impossible to conceive of a total destruction of action as it is of zero which, as we know, is essentially an imaginary number and, strictly speaking, inconceivable. Thus, the association of the soul with Prakrti, however begun, can never come to an end. Vedanta, accordingly, gives us a pure monistic view of life, where Prakrti itself is conceived to be but a form of Brahma or God; and purusha and Prakrti, or the soul and its "subtle body" have always lived together and will do so for ever. Indeed, the soul is said to be born when, in addition to its "subtle body" it comes to possess the "gross" one too, consisting of the five "elements". Vedanta accordingly maintains that the freedom of the soul is achieved not by breaking its bond with Prakrti, as the Sankhya would have us believe, but by a life of equanimity in the midst of all actions, and the experience of pleasure and pain.
The idea of God in the Sankhya: The idea of God can only correspond to that of our highest conception of the soul, for there is no other way of thinking of Him.
The highest conception of the soul, according to the Sankhya, is that, in its purest state, it is characterized by knowledge alone, and is not an actor; and it is also something altogether different from all that is in Prakrti, and has nothing to do with it.
The Sankhya accordingly cannot conceive of God as an actor or creator, and realizes that any other idea of the Deity would be irrelevant. It has accordingly no place for God as a creator in its scheme. It has, however, no objection to a God who is like a liberated soul, that is, one who exists, but has nothing to do with life and its problems; only such a God can be of little use to anyone.
The idea of God in other systems: The idea of God in Nyaya and Vaiseshika, and, to a certain extent, even in Yoga, is an extension of what it is in the Sankhya. Nyaya is prepared to admit that He exists, but believes that He can neither provide nor prevent the results of actions, which are really performed by man. The Vaiseshika does not refer to Him by name as Isvara; but, like the Sankhya, mentions the existence of an Unseen Power, which acts in a variety of ways, especially in the case of extraordinary actions. The Mimansa like the Vaiseshika does not refer to God, but rather to a number of gods who, unlike the Unseen Power, are manifest as the great forms and forces of Nature, governed by a law which is both intelligent and good. Yoga, on the other hand, tells us of an isvara or God who is omniscient and absolute, devotion to whom is essential for success in life as well as to attainment of freedom; but He is conceived to be a special kind of purusha or the individual soul, somewhat like the liberated soul of the Sankhya, but with more clearly defined attributes, for Yoga does not state that He creates. It is only when we come to Vedanta that the Mimansa ideas of the gods, and the Sankhya idea of Prakrti as a good and intelligent Power, are expanded into that of Brahma or God, who is a good and intelligent creator, omniscient and absolute, and who includes all that is in Nature or Prakrti, and yet is something more. Indeed, He is Prakrti itself made divine by partaking of the character of goodness, intelligence as well as joy (Sat-chit-ananda), and the fusion of its idea into that of God. According to the Sankhya, there is a principle of goodness and intelligence, but not of joy, in the universe, not even in good or intelligent action; and what appears to be pleasure is but a form of pain. Vedanta, on the other hand, tells us that life is based fundamentally on the principle of joy; and there is joy both in the process of its creation and continuance; and death is but a door to another form of life; and so when we believe that the great forces of Nature partake of the character of goodness, intelligence, as well as joy in their working, we transform Nature itself into Brahma or God. As the idea of goodness, intelligence, and joy is also expressed in terms of Sacrifice, we might b say that Sacrifice transforms Nature itself into Brahma or God. This is pure monism of God in Vedanta the highest conception of the Deity that the mind of man can grasp, and the culmination of all ancient thought on the subject.
The basic idea of systems of philosophy: We have observed that the different systems of philosophy examine the great problems of life from different points of view, and it is this that accounts for the difference between them. But a little reflection will show that there is a fundamental unity of thought underlying all of them. The Sankhya, as we have seen, is an attempt at an all-inclusive survey of the many problems of life; hut a study of the remaining systems shows that their approach is a more restricted one. This can be explained on the assumption that each of them attempts to survey the same field from a limited angle. We have seen that the Sankhya examines the problem of life in the light of its idea of Prakrti as the supreme creator of things, all except the soul; but in the five remaining systems the centre of thought shifts from Prakrti to Man and his faculties, the senses, mind, ahankara, intellect, and the soul respectively. Man indeed thinks and acts as a single unit, involving the function of all his faculties; but it is possible to lay special stress on any one of them at a particular moment of times, and say that he looks at things in the light of his intellect, or his desires (mind), or his senses. It is in this sense that Nyaya may be said to examine the problem of life in the light of the point of view of the senses; Vaiseshika of the mind; Mimansa of ahankara or the I-as-an-actor; Yoga of the intellect; and Vedanta of the soul. This would explain their differences and divisions, as well as their points of contact and conflict. This would also explain how the six systems can be grouped into three pairs, Sankhya and Yoga, Nyaya and Vaiseshika, and Mimansa and Vedanta (also called Purva-Mimansa and Uttara-Mimansa); and a reference to this has already been made.
This theory of the relation between the five systems of philosophy and the five faculties of man is based on the contents of the systems themselves. As they are all concerned with the chief problems of life, in which the soul occupies the most central place, we should be able to understand the basic idea of each in the light of its conception of the soul; and we find that Nyaya considers the idea of the soul with special reference to the function of the senses, Vaiseshika of the mind, Mimansa of ahankara, Yoga of the intellect, and Vedanta of the real character of the soul itself. According to Nyaya an object is perceived by means of the senses, but only when they function in direct contact with the soul. It is not anxious to specify who the "director" of the senses is, and would be content to call it the "knower", only to explain that the knower can only be the soul. The Vaiseshika tells us that it is only when the mind functions in close connection with the soul, that we can get a clear idea of the soul. The Mimansa speaks of the soul as an actor, and tells us at the same time that the main factor in action is ahankara or the I-as-an-actor, which may be regarded as an aspect of the soul when the latter is said to engage in action. Yoga tells us that the idea of the soul can be grasped by means of reason and reflection, which are a special attribute of the intellect. Finally, Vedanta bases its whole conception of life, including Nature as well as God, on its idea of the soul, regarded as inseparable from its "subtle body") and as knower and actor combined together into one. This will be found to be the main subject-matter of Vedanta.
It has been necessary to give a brief account of the different systems of philosophy in this form; and their text may now be summarized in some detail.