The Upanishads (Sanskrit: उपनिषद्, IAST:Upaniṣad, IPA: [upəniʂəd], are philosophical texts considered to be an early source of Hindu religion.The earliest ones were from before the time of Buddha, 500 B.C.E. They are supposed to be handed down verbally for hundreds of years. "All Upanishads have been passed down in oral tradition." There are over 100 Upanishads like the Katha Upanishad (Dialogue with Death).
Here are a few paragraphs, allowed by fair use of copyright, from a translation of The Upanishads by Eknath Easwaran, Copyright 1987 by Blue Mountain Center of Meditation. Page 115, from The Mundaka Upanishad:
Like two golden birds perched on the selfsame tree,
Intimate friends, the ego and the Self
Dwell in the same body. The former eats
The sweet and sour fruits of the tree of life
While the latter looks on in detachment.
As long as we think that we are the ego,
We feel attached and fall into sorrow.
But realize that you are the Self, the Lord
Of life, and you will be freed from sorrow.
When you realize that you are the Self,
Supreme source of light, supreme source of love,
You transcend the duality of life
And enter into the unitive state.
The Lord of Love shines in the hearts of all.
Seeing him in all creatures, the wise
Forget themselves in the service of all.
The Lord is their joy, the Lord is their rest;
Such as they are the lovers of the Lord.
By truth, meditation, and self-controlPage 117 says:
One can enter into this state of joy
And see the Self shining in a pure heart.
The flowing river is lost in the sea;Elsewhere in these scriptures, it talks about finding a teacher that has achieved this state. It mentions duality which means two different things. In these scriptures, it is referring to the normal experience of feeling that there is you and other people; and there is you and other things.
The illumined sage is lost in the Self.
The flowing river has become the sea;
The illumined sage has become the Self.
The unitive state is where you experience that there is only one thing that exists in reality. They call that one thing the Self or God. This is also referred to as enlightenment or becoming one with God. They also call this one thing consciousness.
Sigmund Freud described an "oceanic feeling" as a sense of limitless and unbounded oneness with the universe. Wikipedia says [This is no longer there now], under Yoga Philosophy, "In all branches of yoga, the ultimate goal is the attainment of an eternal state of perfect consciousness."
It appears that the above quote came from this website putting it up on Wikipedia and someone must have removed it. Yoga Philosophy This says:
In all branches of yoga, the ultimate goal is the attainment of an eternal state of perfect consciousness. Within the monist schools of Advaita Vedanta and Shaivism this perfection takes the form of Moksha, which is a liberation from all worldly suffering and the cycle of birth and death (Samsara) at which point there is a cessation of thought and an experience of blissful union with the Supreme Brahman [God].
The goals of yoga are expressed differently in different traditions. In Hinduism, with its variegated viewpoints and sects, Self-Realization and God-Realization are used interchangeably, with the underlying belief that the true nature of self (truth, consciousness, and bliss), revealed through the practice of yoga, has the same nature as the universal self, which may or may not be identified with a 'creator God' depending on the philosophical standpoint of the practitioner.
In Buddhism, which does not postulate a creator-type god, yoga may help people deepen their wisdom, compassion, and insight. In Western nations, where there is a strong emphasis on individualism, yoga practice may be an extension of the search for meaning in self, and integration of the different aspects of being.Wikipedia says under Yoga:
Yoga (Sanskrit, Pāli: योग yóga) is a physical, mental, and spiritual discipline, originating in modern India whose goal is the attainment of a state of perfect spiritual insight and tranquility. The word is associated with meditative practices in Hinduism, Buddhism and Jainism.