from Christian Science Its “Clear Correct Teaching”, by Herbert Eustace, pages 525-6
The commonly accepted definition of unselfed, by which is meant to be unselfish, is entirely separate from and unlike the metaphysical meaning of the word.
Unselfishness, as humanly interpreted, is full of personalities, and to be unselfish means to be doing for or giving to others, whereas to be unselfed, in the true metaphysical or spiritual sense, is the exact opposite. It has absolutely no personality attached to it. It is centered entirely on God as All-in-all. Every thought begins with God, and flows from Him, enfolding His presentation of Himself in all the beauty, glory and completeness of His own being.
Mrs. Eddy once said, “There is only one way through, and only one, and that is to become unselfed.” Impersonality and unselfedness go hand in hand because both start with God, as causation, and never with effect. Effect, — in other words, what is seen, — to the spiritually minded is like the image in the mirror. Its one and only purpose is to testify to the substance of the image, the object before the mirror, the cause, and never to itself, the effect.
To do this is to become unselfed, and is the only way to be impersonally and spiritually minded.