I have a question on use of a preposition with the ablative. I understand the conventions with relation to towns / cities where prepositions are dropped so we can say Cornelius Roma venit. But it seems that the preposition ab / a is dropped sometimes according to no particular rule. E.g. If we can say; Coenelius equo vehitur can we also say Cornelius ab equo vehitur ?? Or then there’s Servi Mali baculo domini timentur. Could we say Servi mali a baculo domini timentur ?? Both of the examples without the preposition are from Orberg Lingua Latina. Are there rules when you HAVE to use ab / a ?? Orberg doesn’t explain it and I’d be grateful for any guidance.
I don’t think prepositions were dropped, pmda. I think through time they were added for greater clarity w.r.t the “by/with/from” senses. (But many things I think may be wrong, I know.) Other prepositions cover senses not covered by the ablative alone (for example, “in horto [in the garden]”). And instrumental “a/ab” tends to be for people only, not for things.
Minùs, pmda, omittuntur praepositiones, magìs per aeva ad rearum clariùs manifestandum addantur, quosdam sensus ut anglicè “by/with/from” aspicientes. (At falsa, non dubito, multa à me imaginata sint.) Aliae praepositiones res spectant quas ablativus in ipso non significat, exempli gratiâ “in horto”. Instrumentalis usus “a/ab” praepositionis ad homines non res pertinet, ut solet.
Ideò nec “servi mali domino timentur” nec “servi mali à baculo domini timentur” dicimus, sed “servi mali à domino timentur” et “servi mali baculo domini timentur”
Thanks. Yes I think I realised. Ablative of instrument tends not to require Ab / a whereas if a person is involved i.e. doing the thing then Ab a will be used - e.g. Lectica a Syro portatur. Paulus equo vehitur…
In Cornelius equo vehitur, the word equo is ablative of means: “Cornelius is riding on horseback [lit. by means of a horse].” Cornelius ab equo vehitur would mean “Cornelius is being carried by the horse,” with emphasis on the horse’s agency. In the former sentence the horse is merely a method of conveyance, in the latter a wilful agent. This distinction is quite separate from the use of the bare ablative with names of towns, cities, etc. to indicate movement away from a place; the ablative of means and ablative of agent (with ab) do not suggest movement in themselves. Keep in mind that the Latin ablative is a conflation of three separate Indo-European cases (the locative, instrumental, and ablative proper) each with its own unique signification. The ablative with names of towns, cities, etc. is an instance of the ablative proper.
ETA: I don’t really understand what servi mali baculo domini timentur is supposed to mean. Seems nonsensical to me.
Thanks for this. ’ servi mali baculo domini timentur’…I think is nonsensical. Does ‘Servi mali baculo domini verberantur’ make sense? (Bad servants are beaten with the master’s stick’…?’
I didn’t notice that, Imber Ranae. I presumed they were bona fide Orberg examples where timentur must mean “made afraid”, but now you mention it, they do seem odd, since they should mean “are feared”. 
Id non animadverti, imber Ranae. Vera exempla apud Orberg ea credi at nunc dubito. Alienioria videntur, ut dicis.
Was writing the example in a hurry and not paying attention…
Basically, as I understand it, the ablative of agent takes ab/ā and requires that the agent be animate. If the ‘agent’ is not animate, it is really the ablative of instrument and does not take a preposition.
Ab istīs opprimor. – I am being oppressed by these men.
Metū opprimor. – I am being oppressed by fear. [= by means of fear]
Urbs ab istīs dēlēta est. – The city was destroyed by these men.
Urbs flammīs dēlēta est. – The city was destroyed by flames. [= by means of flames]
This is basically the same point Imber Ranae was making, but I wanted to point out that the ablative of agent is always animate (though sometimes inanimate things are personified; fortune – i.e., Fortūna – is one example). Hence, if you’re writing in Latin and you’re describing an inanimate object, you know which one to use. Animate objects tend not to be used with the ablative of means, but, as we see with the ‘equō’ example, they can.
Here’s a humorous example:
Iānua ā Mārcō patefactus est. – The door was opened by Marcus.
Iānua Mārcō patefactus est. – The door was opened by means of Marcus – most likely with Marcus as a battering ram!
Many thanks. I will study this carefully.
Yes, that works.
servi mali baculo domini timentur
Come on guys… nonsensical? Far from it! It’s obvious - ‘The wicked slaves are feared by the master’s rod.’
What? You’ve never seen a rod cowering in the corner as some wicked slaves enter the room?
Mind you I find it hard to get my head around the difference in meaning between active and passive in timeo, timere…
William Whitaker defines ‘timeo etc…’ active as meaning ‘…fear, dread, be afraid of’
What’s the passive of ‘I am afraid of him’? given that passive voice switches the thing / person performing the action;- I hear / I am heard. I did ask before - one would have thought that active would be ‘I frighten him’ and passive would be ‘I am frightened by him’ …
But I suppose ‘I fear him’ and ‘I am feared by him’ does it…so perhaps I’m over analysing it. The trouble is that English idiom doesn’t maintain the distinction.
you rely too much on English translation. LLPSI was not made to learn by translating everything. Just forget the ‘I’m afraid of’ thing.
The subject of TIMERE is the one who has fear. The accusative object of TIMERE is the cause of the fear.
In passive, the subject of TIMERI is the cause of the fear. The ablative is the one who has fear.
CANES TIMEO. Accusative = dogs. Dogs are the cause of the fear. I am the one who has fear.
CANES (A ME) TIMENTUR. Ablative = me. Subject = dogs. Same meaning.
Thanks - that’s clear.