The same reality described by the Rishis is of the Upanishads who were different lot of people much later than the late Vedic Rishis, they also examined God, they also experienced God, and they also came to the conclusion Satchitananda, the reality is pure existence conscious being and the delight. They also described reality as ‘tat sat’. Just as the Vedas spoke of Sat, the Upanishads also described it as ‘tat sat’ so that to describe it as Satchitananda is also to bring him down on a lower plane, it is as it were, at the level at which we can understand him. Because we understand concreteness, we understand consciousness, we understand the delight therefore, we describe it in the highest terms, in the terms that we understand, we describe Him as Satchitananda but in itself if you ask, what is it in itself? The answer of the Upanishads is, it is ‘tat sat’. ‘It is That’ you can't even define it, if you want to say it mathematically, you can say it is’x’. Or as Satprem very often said that it is something else, it is not this, is not that, it is something else; but it ‘Is’, it is something else. But just as in the case of our proposition that God is Pure Existent, we had to take into account the phenomena, in regard to which we had to posit the Pure Being, the phenomena are not exactly the Pure Being, they are those which are in succession, so just as a successive movement required the positing of a Pure Existence, just as the conscious being had to be established in the opposition of the being of the unconsciousness, and we had to explain that unconsciousness is also another mode of consciousness, and therefore, unconscious was reconciled with the conscious being. Even so, there is a phenomenon of pain and pleasure, particularly, in the phenomena of grief, which stands out as a direct contradiction to the existence of God. Although, logically God being Pure Existent and you are conscious, it has got to be concluded that God must be delight, logically that is inevitable.
Yet this question can be raised that if God is really Delight, what is the relationship between that delight and this experience of suffering that we have in the world, provided that there is nothing but only God. If of course, you have theory that God is not the only Reality, there is something else than God then of course this question does not become so stark and so very devastating. But if you've maintained that God is only one and there is nothing else than God, that He is Conscious Being that he is Delight then the presence of experience of suffering is a direct contradiction of that. And then you can say that if God is delight than this experience of suffering does not seem to be congruent with it, therefore, our description of God as Delight becomes challengeable, God must not be Delight because there is experience of suffering, suffering exists. And if there is nothing else but God and he is Delight then how can they be suffering at all, why don't we experience everywhere only delight, why everything is not priyam, why is not everything madhu, why is there suffering in this world. This question has to be answered, and answered properly.
This is the problem, that's why; Sri Aurobindo gives the title "The Problem”. If everything is Pure Existent, Conscious Being and Delight; why is it, how is it, that there is suffering in this world. There are several answers to this question actually, one answer is to say, that there are two origins of the world not one, God alone does not exist there is something else than God also. So you can say that all that is priyam is a result of God, and all that is apriyam is a result of opposite force in the world, which is also original,− this is called Dualism.
Dualism in which God is, as it were, confronted by a shaitan, and where the good is confronted with the evil, and therefore, it is suggested according to this idea that the world is nothing but a battle between the good and the evil and this battle goes on and on and on. And let us see now, what happens in this, we can have faith that ultimately that good will prevail, only faith; you cannot be sure because both are equal forces. But against this Dualism there is one basic opposition, if both of them exist in existence, also there must be both common in existence. So, as far as existence is concerned there must be only one, there can't be two Ultimate Existences, if both exist than both must be common, as far as existence is concerned 16.44 therefore, existence must be One.
Later on, you may discuss as to how the two are different and so on. But as far as Existence is concerned there must be only One therefore, Dualistic Philosophy is always subject to this criticism and therefore, Dualism is not ultimately sustainable. But Dualism can be stated in another form also. It may be argued that God is all Delight, God is all Good, sarvam mangalam, Divine is nothing but mangalam, but God is not omnipotent; this is another way of describing Dualism, God is good but not omnipotent. A limited God, Good God, but limited; if He is not omnipotent, it means that there is a force over which he has no sway, not omnipotent. According to this argument God is good but not being omnipotent, there is existence of another force not exactly coincident with God, therefore, there can be something else than God, it's a kind of dualism. God do is good but not omnipotent is a concept of a kind of dualism because a force is not omnipotent there is some other force, which is not part of God, therefore, there is another Reality outside God.