In my response to your new query,
MORE INFO
In an effort to make my question as short as possible, I abbreviated too much. This is the complete sentence that originated my question:
少年時代から２０年間もずっと過ごしてきて、他人から軽んじられるのに慣れていなかった。
Now you can see what I clipped. I removed important information. Sorry I caused confusion. I've learned how to ask questions better.
I thought you would like the answerer to explain the difference between the above から an に.
If it is wrong, the kindly tell me.
After having researched on the net all through, the above postpositional particle or the conjunctive particle 「から」, which in the Japanese active voice could have 11 meanings such as in English from, by the way of, due to etc, etc,, WHEREAS IN THE JAPANESE PASSIVE VOICE, which is the matter of this question, 「から」 can be used only in quite limited situations., only 2 or 3 cases.
Let's take a look at an example
◆原料・材料の「から」は from
( make と共に使われることが多い）Butter is made from milk.「バターはミルクから作られる。」
Translated ( partly due to the existence of English translation )
Case 1 : から＝from
Example to denote "from some materials", or the "origin".
( I skip to translate some part intentionally due to the reason they have
nothing to do with the Japanese passive voice. )
"Butter is made from milk."
◆相手方を示す「～から・・・される」
文が受身の意味になっている場合 by を用いる
「新しいラケットをおじさんからもらった。」の「から」は文全体が受身の意味になっているので、受動態で、I was given a new racket by my uncle.のようになる。
Translation
Case 2 から＝been XXXXX by
This case can be always seen in the passive voice. The sentence
「I was given a new racket by my uncle.」 indicates the whole sentence should be expressed by the passive voice.
Other researches indicated から, in the passive voice, denote "a starting point".
Considering the meaning of your question, から is used as by.
Let's break down part of your sentence by the component by the component in order for (me) to explain clearly ( sorry ).
他人から軽んじられるのに慣れていなかった。
-->
他人(noun)/から(particle)/軽んじ（verb, "look down", 上一段, here 連用形)/られる（auxiliary, 連体形）/の（particle, 終助詞)/に(later)/慣れていなかった(not be used to XXX )
Now here, the postpostional particle, に, denotes (四）in the link,
since the former postpositional particle の can be swapped by 事, thus considering what the speaker of the sentence is not used to, I concluded
here に denotes the case （四）.
（四）動作・作用の対象、結果を表わす。「車にする」「紙を半分に切る」
Translation
(四）To denote objects, recipients, results etc of the action.
「buy? a car?」 「cut a sheet of paper into 2」
So the roles of the から and に in the sentence is different.
While in the passive voice, に is in the above link same with （六)
( the reasons, methods, etc ),(八),( to denote someone or something that causes the event ), に in the sentence of your question plays a role of （四）
, meaning the objects etc etc ( of the action ( in the above case "to be used to)).
Please note
As I said above,
Other researches indicated から, in the passive voice, denote "a starting point".
So this is my opinion, ( I was not able to find any source with an apology ),
after から in the passive voice, the recipient who receives the movement must exist even after the "movement".
In English man/woman's case, the person ( unknown ) who received the unfavorable feeling that the English man/woman had still exists, while the Tiger's case, the person eaten by the Tiger can not exist anymore. Thus as Brocolli also says, the movement can not occur, therfore, here in this passive voice, the word から can not be used, I thought.
I hope I was able to help you with thank you. Have a nice day.
-----------------------------------------------------------------------------------------------------------------------------------
To me it is a piece of a cake ( or it became a piece of a cake ( I learned even though I am a native speaker....)).
(2) イギリス人から軽んじられた。
「から」,which is used when in the Japanese passive voice something is moved by the de facto subject.
So here, (2), the actual ( de facto ) subject is イギリス人。
What was moved by the イギリス人？ I think it is the feeling of "disregarding", "looking down" etc ( which the English man/woman has inside his/her heart ). The feeling which the English man/woman has was moved to the person ( here unknown ) so that the person can feel he or she is looked down.
Whereas, 虎から食べられた。'case,
Is there anything that the subject 虎 can move or shift to the person?
No, the motion, To eat can not be moved. Upon being eaten, the person ( the object ) dies. So nothing moves. So the latter can take only 「に」here, which denotes simply the actual subject, 虎．
If we talk by the active voice, that might be easier to understand.
The English man/woman looked down on him/her --> The feeling ( which has the English man/woman has ) was moved to the person so that the person can feel he/she is looked down by the English man/woman.
The tiger ate the person --> "To eat" can not be moved because instantly when the tiger eats the person dies......
