How did the PIE root *per- (forward, through) evolve into 'para-', to mean 'contrary to'?

Question

[Etymonline :] ... before vowels, par-, word-forming element meaning "alongside, beyond; altered; contrary; irregular, abnormal," from Greek para- from para (prep.) "beside, near, issuing from, against, contrary to," from PIE * prea, from root * per- (1) "forward, through" (see per). ...

[AHI :] per¹ ...
... IV. Extended form * pr̥əā̆.
...
2. para¹; palfrey, from Greek para, beside, alongside of, beyond.

I don't understand how "forward, through" evolved into one of the meanings of the Greek prefix para-, the one which means 'contrary to'.

Etymonline seems to refer to AHI's particular entry of * per- labelled by the superscript 1, but nowhere does AHI explain this meaning of contrary to. Strangely, AHI designated para with the superscript 1, but AHI only features para once.

Footnote: My research of the etymology of paradox motivated this question.

Answer 1

I think you can observe the same phenomenon with anti (ἀντί), also in Greek which evolves from "in front" to "instead of" and eventually to "against" (more productive in modern languages than in classical Greek).

1. As "in front" in toponymy: Ἀντίπολις => Antibes, Ἀντικύθηρα => Antikythera, etc..
2. As "against": αντίδικος => opponent (same progression and etymology in Latin for opponent and for adversary).

From "in front" to "against", the semantic path is clear.

Similarly for παρά, we progress quite easily from "side by side" to "compared to" and in some cases from "compared to" to "contrary to".

When the object is literally on our side (as in we can lean on it, see s'appuyer, appoggiarsi) then we don’t have an acceptation of "unfavourable".

1. Παρὰ θεοῖς καὶ παρ᾽ ἀνθρώποις => With Gods and men. Favourable.

If instead, the object is out of place (in this sense of παρά: not in its right place) then the idea is that of "different from". This is visible in English in such words as parascience, parapsychology, or even paralinguistics. In classical Greek we have for instance:

2. Παρά μοίραν => Contrary to fate, unfairly. We still have to count with the Moirai but this is probably not a favourable factor.

3. Παράδοξος => Out of (contrary to) δόξα expectation, opinion

English also uses beside to suggest this kind of opposition. Maybe after all this explanation is beside the point.

So in conclusion, the intended meaning is not as much 'against' (which would be κατά or ἀντί) as '[unexpectedly] different'.

Edit

The English word with followed a symmetrical/opposite evolution.
(A brief digression: Using "symmetrical" to mean "opposite" is also quite revealing.)
- In Old English wið meant "against" (it still does in withstand or withsay for instance). From Proto-Indo-European *wi ("separation").
- Now with means "alongside".
So this time the semantic shift seems to be "separate" => "face to face" => "alongside".
For instance if you pit two armies face to face they actually form parallel lines.

Answer 2

I think it is pretty logical: to go against someone or something, you must first go towards it. For example, in Swedish both meanings are expressed with the same preposition mot:

• ett tåg mot Stockholm = a train to Stockholm
• kampen mot rasism = the fight against racism
• vända sig mot solen = to turn towards the sun
• vända sig mot fienden = to turn against the enemy

Answer 3

Greek prepositions and the verbal prefixes derived from them are a bit mysterious as their various meanings are often very heterogenous. My assumption is that in some prepositions several words have flowed together, which is easily possible if we consider the fact that Old Greek is not a homogeneous language but a side-by-side of various dialects which can influence each other.