How did sollicitāre ‘disturb, agitate’ semantically shift to the meaning of "manage affairs"? I don't understand because "disturb, agitate" pejoratively connotes discontentment and upheaval, but "manage affairs" neutrally (or even positively) connotes business or transactions. This shift in connotation also baffles me.
For example, in some Commonwealth countries' split legal profession, a "solicitor" signifies a lawyer for non-contentious matters who provides general advice. A solicitor doesn't "disturb, agitate" in 2021 English meanings of these verbs.
The ultimate source of solicit is Latin sollicitus ‘agitated’, which also gave English solicitous . It was a compound adjective, formed from sollus ‘whole’ (source also of English solemn) and citus, the past participle of ciēre ‘move’ (source of English cite, excite, etc) – hence literally ‘completely moved’. From it was formed the verb sollicitāre‘disturb, agitate’, which passed into English via Old French solliciter. By the time it arrived it had acquired the additional meaning ‘manage affairs’, which lies behind the derived solicitor ; and the original ‘disturb’ (which has since died out) gave rise in the 16th century to ‘trouble with requests’.
French insouciant, borrowed by English in the 19th century, goes back ultimately to Latin sollicitāre.
Word Origins (2005 2e) by John Ayto, p 467 Left column.