The world, as it appears, is found to be lacking in reality, and so, is unreal. Hence the need for the higher Light.

"What is That by knowing which this everything becomes known?" -Mundaka Upanishad 1. 1.3. 

"By which the Unheard becomes heard, the Unthought becomes thought, the Ununderstood becomes understood." -Chh. Up. VI. 1. 3. 

The knowledge of everything through the knowledge of One Thing implies that everything is made up of that One Thing. That the misconception of things being really made of differing natures has to be set aright is pointed out by the disgust that arises in clinging to the notion of the multiple permanence of beings and a passion for catching completely whatever that must exist. The growth of intelligence tends towards urging the individual to grasp the totality of existence at a stroke. This constructive impulse is inherent and is vigorously active both in the instinctive mind and the scientific intellect. The individual is a consciousness-centre characterised by the imperfections of limitation, birth, growth, change, decay and death. Thought is objectified consciousness. The greater the objectification, the denser is the ignorance and the acuter are the pains suffered.

Truth does not shine as Truth, owing to the inner instruments, the clogging psychological modifications. The crossing the barrier of these limiting adjuncts seems to lead one to a vaster reality, greater freedom and fuller life. There is a common desire-impulse in every being to exist for ever, to know all things, to domineer over everything, and to enjoy the highest happiness. The statement of the Upanishads that the cognition of manifoldness is the path leading to self-destruction is adorned by the supreme exhortation that the perception of Unity to the exalted state of Immortality.

Every form of cogitation in spite of individualistic cravings that may try to obstruct it, flows, being impelled by an imperceptible power that moves towards the recognition of the indivisibility of existence, and a finding of oneself in the centre of its experience. The aspiration of every living being is to find rest in the blissful possession of eternal life, and nothing short of it. The sorrow of phenomenal life is rooted in the clinging to relational living fed by the wrong notion that manifoldness is the truth. The joy of the immensity of everlasting life is partaken of by cutting the root of the tree of individual life with the axe of integrated wisdom. The march of the soul is from the false to the true, from the apparent to the real, from the shadow to the light, from the perishable to the ever-enduring.

"From the unreal lead me to the Real, from darkness lead me to Light, from death lead me to Immortality." -Brih. Up. 1. 3. 28.

Everyone is marked by the general character of the struggle to become infinitely perfect. This Infinite Being is the highest Truth. This is the Goal of the life of all. The Upanishads stress in a hundred ways upon the need for this integral knowledge of Reality. There is nothing greater than or equal to the knowledge of the Atman. Atmalabhat na param vidyate.

"This Atman, which is free from evil, undecaying, deathless, sorrowless, hungerless, thirstless, whose desire is Truth, whose will is Truth - That should be searched after, That should be known. He obtains all worlds and all desires who has known and who has realised That Atman. -Chh. Up. VIII. 7. 1.

"Know That, the Brahman. -Taita Up. III. 1.

"For the sake of the knowledge of That, he should go, fuel in hand, to a spiritual preceptor alone, who is learned in the scriptures and established in Brahman. -Mund. Up. 1. 2. 12.

The purpose of life on earth is the realisation of this stupendous depth of the Being of all beings, without which life becomes a failure. "If one would know it here, then there is the true end of all aspirations. If one would not know it here, then great is the loss for such a person. Knowing it in every particular being, the wise, on departing from this world, become immortal" (Kena Up. II. 5). There is a severe reproach to those who do not attempt at and succeed in the realisation of Truth.

"Godless are those worlds called, with blind darkness covered over, to which, on death, those who are the slayers of the Self go." -Isavasya Upanishad 3. 

"He, who departs from this world without knowing That Imperishable Being, is wretched." -Brih. Up. III. 8. 10.

The teacher of the Brahmavidya is praised in glowing terms.

"You, truly, are our father, who take us across to the blessed other shore of ignorance." -Prashna Up. VI. 8.

The love for the Eternal is the essential passion that burns in the heart of all things. Beings know it not, and so they suffer. When we turn our face away from this one Reality, we open the door to self-imprisonment. No achievement, either on earth or in heaven, no greatness pertaining to the world of name and form, is worth considering. The love of life is based on the love of the Self.

"Not, verily, for the love of the all is the all dear, but for the love of the Self is the all dear." -Brih. Up. II. 4. 5.

All actions are done for the sake of the Self, not for external persons and things. It is not the existence of joy in the object as such that brings pleasure to the individual enjoying it, but the cooling of the fire of craving that is brought about by its contact with a particular object which is specially demanded by that special mode of desire generated in the ego-consciousness. The satiation is caused by a temporary turning back of the mind to the Self. The whole of the happiness of the world is, thus, purely negative, an avoiding of the unpleasant, and not the acquirement of any real, positive joy. This positive bliss is found only in the Self, the root of existence. The bustle of life's activity is a struggle to respond to the cry of the anxious ego which has lost itself in the wilderness of its separation from the Eternal Principle. The grieving self bound by fetters in the prison of life is ransomed by the knowledge of the non-dual nature of Existence.