Oxford English Dictionary: SELF: The ultimate etymology is obscure; many scholars regard the word as a compound of the pronominal stem se- .... In Goth. and Scandinavian the primary sense (= L. ipse) is the only one that exists; the sense of 'same', found in Eng. and the other WGer. langs., was developed from this in collocations where the notion of identity implied by a demonstrative was emphasized by the additon of self (thus the OE. se selfa man Se may be rendered either 'the very man who' or 'the same man who').

e. In generalized sense.
1826 Disraeli Viv. Grey i. x. 63 Self is the only person whom we know nothing about.
2. transf. in various uses, +esp. a person whom one loves as oneself or is a counterpart of oneself (obs. exc. in other self, second self: see second a.).
1605 1st Pt. Jeronimo ii. iv. 49 Welcome, my selfe of selfe.
1671 H. M. tr. Erasm. Colloq. 4 Heavens grant you a safe return. God keep thee my half self.
a.1700 Ken Hymnotheo Poet. Wks. 1721 III. 115 But when the Babe breaks out into the Light, Soon as her little self is in her sight,..She feels a Mother's Bowels yearn within.
1763 C. Johnston Reverie II. 133 The tender connexions of nature, which, as it were, multiply a man into many selfs for the safety of each dear particular of whom, his anxiety is greater than for his own.
1771 H. Walpole Vertue's Anecd. Paint. (1786) III. 139 My dear heart and self and son Charles.
1827 Hood Mids. Fairies xliv, We shall not die nor disappear, But, in these other selves ourselves succeed.
1858 Stanley Life Arnold I. iii. 89 Our 'great self', the school.
3. Chiefly Philos. That which in a person is really and intrinsically he (in contradistinction to what is adventitious); the ego (often identified with the soul or mind as opposed to the body); a permanent subject of successive and varying states of consciousness.
a.1674 Traherne Poet. Wks. (1903) 49 A secret self I had enclos'd within,
That was not bounded with my clothes or skin.
1682 Sir T. Browne Chr. Mor. i. §24 The noblest Digladiation [fighting or wrangling] is in the Theater of our selves.
1690 Locke Hum. Und. ii. xxvii. §9 Since consciousness always accompanies thinking, and 'tis that, that makes every one be, what he calls self.
Ibid. §17 Self is that conscious thinking thing, whatever Substance, made up of Spiritual, or Material, Simple, or Compounded, it matters not, which is sensible, or conscious of Pleasure and Pain,..and so is concern'd for it self, as far as that consciousness extends.
1713 Berkeley Hylas & P. iii. Wks. 1871 I. 329, I, one and the same self, perceive both colours and sounds.
1862 Spencer First Princ. i. iii. §20 (1875) 65 If, then, the object perceived is self, what is the subject that perceives? or if it is the true self which thinks, what other self can it be that is thought of?
1865 J. H. Newman Dream Ger. 5th Choir, Praise to the Holiest, God's Presence and His very Self And Essence all~divine.
1865 Mill Exam. Hamilton 207 Reid seems to have imagined that if I myself am only a series of feelings, the proposition that I have any fellow-creatures, or that there are any selves except mine, is but words without a meaning.
1866 Duke of Argyll Reign of Law i. (1867) 8 But these selves of ours do belong to Nature.
1871 Meredith H. Richmond lv, In reality the busy little creature within me, whom we call self, was digging pits for comfort to flow in, of any kind, in any form.
1877 E. R. Conder Bas. Faith iv. 184 But Self does not come and go; it abides. Self, therefore, is not a phenomenon, nor yet a bundle of phenomena.
1899 Allbutt's Syst. Med. VIII. 267 Insanity has been already defined as defect or disorder of the process of adjustment of self to circumstances.
Ibid. 288 So long as the 'self' is not implicated in what is done by the body, the self is not responsible and cannot justly be punished.
1909 Chesterton Orthodoxy iii. 63 You cannot call up any wilder vision than a city in which men ask themselves if they have any selves.
4. a. What one is at a particular time or in a particular aspect or relation; one's nature, character, or (sometimes) physical constitution or appearance, considered as different at different times. Chiefly with qualifying adj., (one's) old, former, later self.
1697 Dryden Virg. Georg. iii. 160 In vain he burns..And in himself his former self requires.
a.1711 Ken Div. Love Wks. (1838) 282 My duty of loving those best, which either in blood are nearest my natural self, or in grace nearest my Christian self.
1746 Francis tr. Horace, Epist. i. x. 66 If e'r, forgetful of my former Self, I toil to raise unnecessary Pelf.
1841 C. Fox Jrnl. 30 Sept. (1972) 115 Dr. Calvert..was quite his old self, talking on his old subjects in his old way.
1858 O. W. Holmes Aut. Breakf.-t. ix. (1859) 211 How pleasant it would be, if in another state of being we could have shapes like our former selves for playthings.
1910 'Mark Rutherford' Pages fr. Jrnl. (ed. 2) 268 The self of two hours before seemed to confront him.
1975 H. Fleetwood Picture of Innocence x. 177 You seem quite like your old self again.
b. An assemblage of characteristics and dispositions which may be conceived as constituting one of various conflicting personalities within a human being. better self: the better part of one's nature.
1595 Spenser Amoretti xlv. 3 And in my selfe, my inward selfe I meane, Most liuely lyke behold your semblant trew.
a.1703 Burkitt On N.T. Mark xii. 34 Every man may, yea, ought to love himself: not his sinful self, but his natural self: especially his spiritual self, the new nature in him.
1820 Keats Lamia 170 In self despite, Against his better self.
1849 Sir J. Stephen Eccl. Biog., I. Taylor II. 389 So, indeed, resolved the Self inhabiting one of the phrenological hemispheres within me. But the resolution was ultimately reversed by the superior energy of the Self who reigned over the opposite hemisphere.
1866 G. Macdonald Ann. Q. Neighb. vii. (1878) 125 Whatever your lowest self, and not your best self may like.
1867 Goldw. Smith 3 Eng. Statesmen (1882) 45 Our nation..had to go through greater trials, and be thrown more upon its nobler self, before it could deserve victory.
1908 R. Bagot A. Cuthbert x. 116 Sonia di San Vico was asking herself whether this were love... For the first time in her life that other self of hers gave no satisfactory reply.
5. One's personal welfare and interests as an object of concern; chiefly in bad sense, selfish or self-interested motives, selfishness.
a.1680 Charnock Attrib. God (1682) 70 Self is the great Anti-Christ and Anti-God in the World.
1725 Watts Logic ii. iii. §3 Were it not for this Influence of Self and a Bigotry to our own Tenets, we could hardly imagine that so many..wicked..Principles should pretend to support and defend themselves by the Gospel of Christ.
1782 F. Burney Cecilia viii. iii, But self will still predominate.
1842 Tennyson Locksley Hall 34 Love..Smote the chord of Self, that, trembling, passed in music out of sight.
1855 Kingsley Westw. Ho! ii, One who had long since learned to have no self, and to live not only for her children, but in them.
1859 Geo. Eliot Adam Bede liv, She's better than I am-there's less o' self in her, and pride.
1870 Mozley Univ. Serm. iii. (1877) 67 This respect to self and its ultimate good pertains to the very nobility of man's nature.
1906 C. Mansfield Girl & Gods xix, Self is their god and Selfishness their religion.
II. From the adjective.
6. (Cf. B. 3 b.)
a. A 'self-coloured' flower: esp. applied to carnations.
1852 G. W. Johnson Cottage Gard. Dict., Self, a flower with petals of only one colour.
1869 Contemp. Rev. XI. 149 Some of her characters are too much what a florist would call 'selfs'-all one colour.
1892 Garden 27 Aug. 194/2 The majority of present-day kinds [of Carnations]-I allude chiefly to garden selfs-are..scentless.
b. Something (as an animal or garment) of a single colour.
1930 R. A. Fisher Genet. Theory Nat. Selection vii. 165 Rats of both selected lines were bred back to unselected selfs.
1978 Lochaber News 31 Mar. 2/1 (Advt.), 'Dereta' coats, superb collection of tweeds and selfs in a variety of fabrics, designs and colours.
7. A self bow. (See B. 6.)
1856 H. A. Ford Archery iii. 14 Ascham..mentions none other than selfs.
D. -self in compound pronouns. For the diverse grammatical character (partly adj., partly n.) of this element in myself, thyself, himself, herself, itself, ourselves, yourselves, themselves, oneself, and for illustration of the emphatic and the reflexive functions of these words, see the several articles. Certain phraseological uses common to the whole group in their capacity of reflexive pronouns may conveniently be noticed here.
1. to be --self:
a. colloq. To be in (one's) normal condition of body or mind; to be in (its) accustomed state. Also to feel like --self.
For other examples see himself 3 b, myself 4 b, themselves 2 b.
1849 Macaulay Hist. Eng. v. I. 644 The chief justice was all himself. His spirits rose higher and higher as the work went on.
1884 Daily News 23 May 5/3 Mr. Grace was all himself [at cricket].
b. To act according to one's true character, without hypocrisy or constraint.
1864 [see myself 4].
1896 'M. Field' Attila i. 26 Only the courage seems impiety For just a girl to dare to be herself.
2. The refl. pron. assumes in certain contexts the sense: The normal condition (of the person or thing). So to come to --self (come v. 45 h), to bring, restore to --self. out of --self (? now rare), + from --self, beside --self (see beside prep. 5 a): out of (one's) mind or senses, deranged.
a.1450 Knt. de La Tour iii. (1906) 6 And he was so sore afraied and aferde, that he ranne awaie as he had be oute of hym selff.
c1489 Caxton Blanchardyn xii. 43 She fell doune from her ain beere as a woman from her self and in a swone.
1659 B. Harris Parival's Iron Age 17 France being..restored to her self, as well by the help of forreigners, as of her Neighbours.
1727 Swift Furth. Acc. E. Curll Misc. 1732 III. 30, I never perceived he was out of himself, till that melancholy Day that he thought he was poison'd in a Glass of Sack.
1846 Digby Broad Stone Hon. II. Tancredus 301 A novice of the order of St. Francis being now almost out of himself, struggling with death cried out [etc.].
1856 C. M. Yonge Daisy Chain i. xix. (1879) 192 But Tom, who seemed fairly out of himself, would not stir.
3. by --self: alone, without society; unaided; separately. See by prep.
c888 K. Ælfred Boeth. xxxv. §6 Ne mæ1/4 nan o[dhatch]ru 1/4esceaft be him selfum bion.
a.1300 Cursor M. 1714 Se meke [beist] be Sam ai tua and tua, Se wild do be Sam-self al-sua.
c1386 Chaucer Reeve's T. 222 Noght from his owene bed ten foot or twelue His doghter hadde a bed al by hir selue Right in the same chambre by and by.
1448 in Willis & Clark Cambridge (1886) II. 8 All the bemes that lyen by hemself.
c1449 Pecock Repr. v. xv. 564 A[Sinvcircumflex]ens this..is maad a book by him silf clepid the Book of Faith.
1573 Treas. Hid. Secrets xiii, This wise you may make Marmalade of wardens, peares, apples &c..everyone by himself.
1581 G. Pettie tr. Guazzo's Civ. Conv. i. (1586) 17 b, It is dailie seene that a man being by himselfe is fearefull, and being in companie, is couragious.
1610 Shakes. Temp. i. ii. 221 The Kings sonne haue I landed by himself.
1711 Addison Spect. No. 12 33, I am mistaken if he ventures to go to Bed by himself this Twelve-month.
1857 Mrs. Carlyle Lett. II. 308 Mr. C. dines all by himself at present, I merely looking on.
1889 Saintsbury Ess. Eng. Lit. (1891) 65 If Hogg in some lucky moment did really 'write it all by himself', as the children say.