Apologia, apologie = a reasoned defence of one’s opinion, beliefs or conduct
Apology = expression of guilt or remorse + all the other similar meanings listed in dictionaries
The original meaning of the Greek “APOLOGIA” was “to defend one’s opinion or conduct”, or “self-justification”. “APOLOGY” first appeared in the 16th century in the English language (see below), but it soon acquired the meaning of “regret” or “remorse”. In order to remedy this, “apologia” was reintroduced in the 18th century.
“APOLOGIE” was an archaic spelling of the word, possibly borrowed from French (quite common practice in those days).

“The meaning of apology has evolved a good deal since its first appearance in the sixteenth century (the first use recorded in the OED is in the title Apologie of Syr Thomas More, Knyght; made by him, after he had geuen ouer the Office of Lord Chancellor of Englande, dated 1533). In this Sir Thomas More was not regretting his actions: he was seeking to justify himself and to defend himself from accusations. Another example is An Apology for the Life of Mr Colley Cibber (Comedian) in 1740 by the English actor-manager who was answering his critic Alexander Pope with details of his life’s achievements; here the word is a pun on the older sense and our modern one, it being a fake apology which is actually a justification. A century later, Cardinal Newman wrote “Apologies for various of the great doctrines of the faith” and Samuel Butler coined this little squib in 1912:
Apology for the Devil: It must be remembered that we have only heard one side of the case. God has written all the books.
in which apology has this original sense of a defence of one’s opinions or conduct and not an expression of guilt or remorse. All these look odd to us today, though the sense is not yet entirely obsolete.
This meaning comes directly from the Greek apologia, a derivative of a word meaning “to speak in one’s defence”, ultimately from the prefix apo-, “away; off” (which turns up at the start of lots of English words, such as apogee for the point in an orbit furthest from the orbited body, and in the Biblical Apocrypha, which means books “hidden away”) together with logos, “speech” (from which we get our word logic). From this Greek original, it entered English either through French or Latin.
It was quite soon after its first appearance that the meaning of apology began to shift away from self-justification towards implying regret. This change seems to have occurred in two stages. Firstly, it was used to describe the process of excusing oneself from the wrath of a person affected by one’s actions with the explanation that no offence was intended, a sense of modified self-justification which again is still found today. Then the use moved further to acknowledge that some offence had in fact been given and to express regret—exactly our main modern sense. The first example turns up in that unique recorder of Elizabethan English, William Shakespeare (in Richard III).
So much did the sense change that English eventually required a new word to express the original meaning. In the eighteenth century the Latin intermediary, apologia (/ /) was borrowed again, though it only gained widespread acceptance after Cardinal Newman used it in 1864 in the title of his famous work Apologia pro Vita Sua, “A defence of his life”, in response to Charles Kingsley’s attacks on his religious convictions.”
http://www.worldwidewords.org/topicalwords/tw-apo1.htm