“In conscious life, we achieve some sense of ourselves as reasonably unified, coherent selves, and without this action would be impossible. But all this is merely at the ‘imaginary’ level of the ego, which is no more than the tip of the iceberg of the human subject known to psychoanalysis. The ego is function or effect of a subject which is always dispersed, never identical with itself, strung out along the chains of the discourses which constitute it.”

The Tragic Sense of Life (1913), VI : In the Depths of the Abyss
Context: To all this, someone is sure to object that life ought to subject itself to reason, to which we will reply that nobody ought to do what he is unable to do, and life cannot subject itself to reason. "Ought, therefore can," some Kantian will retort. To which we shall demur: "Cannot, therefore ought not." And life cannot submit itself to reason, because the end of life is living and not understanding.

The Doors of Perception (1954)

Ch. 11 : LSD Experience and Reality http://www.psychedelic-library.org/child11.htm
LSD : My Problem Child (1980)
Context: Of greatest significance to me has been the insight that I attained as a fundamental understanding from all of my LSD experiments: what one commonly takes as "the reality," including the reality of one's own individual person, by no means signifies something fixed, but rather something that is ambiguous — that there is not only one, but that there are many realities, each comprising also a different consciousness of the ego.
One can also arrive at this insight through scientific reflections. The problem of reality is and has been from time immemorial a central concern of philosophy. It is, however, a fundamental distinction, whether one approaches the problem of reality rationally, with the logical methods of philosophy, or if one obtrudes upon this problem emotionally, through an existential experience. The first planned LSD experiment was therefore so deeply moving and alarming, because everyday reality and the ego experiencing it, which I had until then considered to be the only reality, dissolved, and an unfamiliar ego experienced another, unfamiliar reality. The problem concerning the innermost self also appeared, which, itself unmoved, was able to record these external and internal transformations.
Reality is inconceivable without an experiencing subject, without an ego. It is the product of the exterior world, of the sender and of a receiver, an ego in whose deepest self the emanations of the exterior world, registered by the antennae of the sense organs, become conscious. If one of the two is lacking, no reality happens, no radio music plays, the picture screen remains blank.

Source: All Flesh is Grass (1965), Chapter 12 (p. 123)

#ego

Mathematical and Physical Papers, Vol.1 http://books.google.com/books?id=nWMSAAAAIAAJ p. 512 (1882) "On a Universal Tendency in Nature to the Dissipation of Mechanical Energy" originally from the Proceedings of the Royal Society of Edinburgh for April 19, 1852, also Philosophical Magazine, Oct. 1852
Thermodynamics quotes

Be As You Are, The Teachings of Sri Ramana Maharshi (1985) http://www.sadgurus-saints-sages.com/books/RamakrishnaParamahamsa/beasyouare.pdf

E 69
Aphorisms (1765-1799), Notebook E (1775 - 1776)

1920s, The Ego and the Id (1923)