Roberto Assagioli about Eternity from his booklet Meditation for The New Age, Year Three:
“In connection with the concept of Eternity, we should realise that this word has two meanings: the one just referred to, unlimited duration of time, and the other, which is in a sense the opposite—the permanent, unchanging, ever-present Reality. It has been called the Eternal Now, and it relates to a level or state of consciousness beyond time and space.” …
“The writings of many of the great mystics and seers of both East and West are illuminating and helpful for this purpose. Many of them have experienced in their moments of illumination a real sense of eternity, or timelessness, and in Evelyn Underhill’s excellent book Mysticism the experiences of many of the Christian mystics are recounted. Cosmic Consciousness by Dr. Richard Maurice Bucke is also a most informative book on this theme, being a valuable series of reports of experiences of this high nature, with able comments on them.
However, the more direct technique for expanding our consciousness is, as just said, meditation. In it the centre of consciousness is propelled upwards by aspiration and will towards higher regions of being—towards the Transcendent Reality mentioned at the beginning of this Course. The inner experiences or realisations thus achieved are really inexpressible, but it can be said that they bring about an increasing realisation of the identity of one’s spiritual Self with all Selves and with the ONE SELF.