What is "to be beside one's self"

Beside \Be*side"\, prep. [OE. biside, bisiden, bisides, prep. and adv., beside, besides; pref. be- by + side. Cf. Besides, and see Side, n.]

1. At the side of; on one side of. ``Beside him hung his bow.''
   --Milton.

2. Aside from; out of the regular course or order of; in a state of deviation from; out of.

   [You] have done enough To put him quite beside his patience.
   --Shak.

3. Over and above; distinct from; in addition to.

   Note: [In this use besides is now commoner.]

   Wise and learned men beside those whose names are in the Christian records.
   --Addison.

   To be beside one's self, to be out of one's wits or senses.

   Paul, thou art beside thyself.
   --Acts xxvi. 2

4. Syn: Beside, Besides. Usage: These words, whether used as prepositions or adverbs, have been considered strictly synonymous, from an early period of our literature, and have been freely interchanged by our best writers. There is, however, a tendency, in present usage, to make the following distinction between them:

   1. That beside be used only and always as a preposition, with the original meaning ``by the side of; '' as, to sit beside a fountain; or with the closely allied meaning ``aside from'', ``apart from'', or ``out of''; as, this is beside our present purpose; to be beside one's self with joy. The adverbial sense to be wholly transferred to the cognate word.

   2. That besides, as a preposition, take the remaining sense ``in addition to'', as, besides all this; besides the considerations here offered. ``There was a famine in the land besides the first famine.''
      --Gen. xxvi. 1. And that it also take the adverbial sense of ``moreover'', ``beyond'', etc., which had been divided between the words; as, besides, there are other considerations which belong to this case. The following passages may serve to illustrate this use of the words:

      Lovely Thais sits beside thee.
      --Dryden.

      Only be patient till we have appeased The multitude, beside themselves with fear.
      --Shak.

      It is beside my present business to enlarge on this speculation.
      --Locke.

      Besides this, there are persons in certain situations who are expected to be charitable.
      --Bp. Porteus.

      And, besides, the Moor May unfold me to him; there stand I in much peril.
      --Shak.

      That man that does not know those things which are of necessity for him to know is but an ignorant man, whatever he may know besides.
      --Tillotson.

      Note: See Moreover.