In religious use, enlightenment is most closely associated with South and East Asian religious experience, being used to translate words such as (in Buddhism) bodhi or satori, or (in Hinduism) moksha. The concept does also have parallels in the Abrahamic religions (in the Kabbalah tradition in Judaism, in Christian mysticism, and in the Sufi tradition of Islam).
In secular use, the concept refers mainly to the European intellectual movement known as the Age of Enlightenment, also called the Age of Reason referring to philosophical developments related to scientific rationality in the 17th and 18th centuries.
The lotus flower is sometimes used as a symbol of enlightenment.
The lotus has its roots in the mud,
Grows up through the deep water,
And rises to the surface.
It blooms into perfect purity and beauty in the sunlight.
It is like the mind unfolding to perfect joy and wisdom.
A buddha, or fully enlightened one, is regarded as a sentient being who has developed all positive qualities, and has eradicated all negative qualities, and with complete wisdom sees things "as they are."
Enlightenment in Zen (called Satori) is the state of being with no "little" mind. It is the disappearance of the ego. It is the loss of all identification with the body and the mind. It is freedom from beliefs, opinions, ideals and concepts. Satori is always sudden, because it is not an achievement; it is already the case. It is a remembering. In Zen it is called the pathless path, that is, it is not something to be achieved, but it is to be Realized and lived. Meditation, with no thought, simply watching, watching the breath, is the initial method to create the space for its occurrence.
In the Western philosophical tradition, enlightenment is seen as a phase in cultural history marked by a faith in reason, generally accompanied by rejection of faith in revealed or institutional religion.
In his famous 1784 essay What Is Enlightenment?, Immanuel Kant described it as follows:
Kant reasoned that although a man must obey in his civil duties, he must make public his use of reason. His motto for enlightenment is Sapere aude! or "Dare to know."
In Human, All Too Human, philosopher Friedrich Nietzsche had this to say about enlightenment and the understanding of good and evil:
Some individuals who are said to be enlightened did so without any visible tradition or lineage like Dave Oshana, John de Ruiter and Barry Long (dec'd).
Osho is said to have achieved enlightenment at the age of 21 after many years of spiritual, religious and academic indulgence.
Nārāyana Guru (1856–1928), the prolific poet, philosopher, and social reformer is believed to have attained enlightenment (i.e., an absolute state of wisdom) after his several years of education in languages, the scriptures of the different religions, yoga, and experiences with ascetic life, culminating in his long and meditative recluse in Maruthwamala hills in South India. Nārāyana Guru’s philosophical masterpiece “Atmopadeśa Śatakam” (100 verses of self-instruction) is primarily the Guru’s poetic expression of his philosophy of universal love, emanating from his experienced state of primordial knowledge of the Universe, and his consequent ability to view the human race as one of a species, in unqualified equality and without any racial, religious, caste, or other discriminations whatsoever.
Dr. Richard Bucke, in his 1901 book Cosmic Consciousness
, names a few dozens of people who, in his studied opinion, had experienced some degree of enlightenment, including Walt Whitman and Blaise Pascal. Bucke also attempted to analyze what commonalities these personalities shared. His study has become part of the foundation of transpersonal psychology. There are some thinkers such as U. G. Krishnamurti, who refute any existence of the very concept of enlightenment (despite being considered enlightened by his followers).
Spiritual writer Eckhart Tolle is said to have attained enlightenment at age 29 after suffering long periods of depression.
Aikido founder Morihei Ueshiba is said to have become enlightened after defending himself from the attacks of an exceptional swordsmen with only his bare hands.