Could it be that there is any object in this construction? As I understand it, litterally reading, it says
“to withdraw from a place in favor of someone”
and thus
“to give place to someone”
So, I read an ablative proper and a dative of interest denoting the person in advantage of which something is done. Am I right?
Yes, you’re right.
loco is ablative; alicui is dative–dative of interest.
It would be helpful to see this in some context.
Thank you for replying, Hylander!
I know what case is each argument. My question is whether can any of these arguments (ablative-dative) be read as “objects” (obviously “indirect objects”) or not.
Here is a passage (From Valerius Maximus. Facta et Dicta Memorabilia):
At Caecilia Metelli, dum sororis filiae, adultae
1.5.4.2
aetatis uirgini, more prisco nocte concubia nuptiale
petit omen, ipsa fecit: nam cum in sacello quodam
eius rei gratia aliquamdiu persedisset nec [aliqua]
1.5.4.5
ulla uox proposito congruens esset audita, fessa
longa standi mora puella rogauit materteram ut sibi
paulisper locum residendi adcommodaret. cui illa
‘ego uero’ inquit ‘libenter tibi mea sede cedo’.
quod dictum ab indulgentia profectum ad certi omi-
1.5.4.10
nis processit euentum, quoniam Metellus non ita
multo post mortua Caecilia uirginem, de qua loquor,
in matrimonium duxit.
And another with no dative:
(C. Sal.Crispus. Catilinae Coniuratio)
duabus his artibus, audacia in bello, ubi pax evenerat aequitate,
9.4.1
seque remque publicam curabant. quarum rerum ego
maxuma documenta haec habeo, quod in bello saepius
vindicatum est in eos, qui contra imperium in hostem
pugnaverant quique tardius revocati proelio excesse-
9.4.5
rant, quam qui signa relinquere aut pulsi loco cedere
9.5.1
ausi erant; in pace vero quod beneficiis magis quam
metu imperium agitabant et accepta iniuria ignoscere
quam persequi malebant.
Thanks a lot, again.
I think you have answered your own question. The dative is the indirect object and there is no expressed direct object. “I withdraw from my seat in favour of you”. Cedo can take a direct object but in the passage you cited the author wants to emphasis the moving away from aspect of the verb rather than “the yielding something to someone”. I think it would be helpful to look at the range of constructions which cedo can be used in and the shades of meaning here in L&S http://www.perseus.tufts.edu/hopper/morph?l=cedo&la=la&can=cedo0&prior=sede&d=Perseus:text:2008.01.0675:book=1:chapter=5:section=4&i=1#lexicon
Gratias tibi, Seneca2008!
To tell you the truth I’ ve already read from Lewis & Short Lexicon. Someone told me that the ablative is (or functions as) a DIRECT object, while the dative is the indirect. But there are no means by which I can understand this…
What I needed was anykind of verification, or perhaps better confirmation… And both you and Hylander have done that. I’ve found more here:
At the beginning I considered this dative to be a Dative of Advantage (http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0001%3Apart%3D2%3Asection%3D9%3Asubsection%3D12%3Asmythp%3D376). But Allen-Greenough, at least, say it is an indirect object.
Now I’ m going on with Gildersleeve-Lodge and I’ ve already looked in Woodcock (what a nice book by the way)…
Thank you very much anyway!
Indirect object, dative of advantage–the Romans didn’t think in terms of these categories. They just knew when to use the dative; and the categories themselves are not necessarily sealed off from one another.
A&G notwithstanding, dative of advantage in the cedere loco alicui idiom seems better to me because cedo is intransitive in this usage, and it means simply “go” or "go from.
loco is ablative and is NOT the direct object of cedere. In English translation, “to give up one’s place to someone,” “place” is the direct object of “give up” (and “someone” is the indirect object"), but that’s not how the Latin idiom works, which is literally “to go from place to/for someone.”
I entirely agree with Hylander. I tend to put indirect object and dative of advantage in the same category and loosely talk about both of them as indirect objects. They clearly both involve the same idea.
Someone told me that the ablative is (or functions as) a DIRECT object
I can see that this incorrect inference might be made from the JB Greenough
" Cēdō, yield, sometimes takes the Ablative of the thing along with the Dative of the person: as,cēdere alicui possessiōne hortōrum (cf. Mil. 75), to give up to one the possession of a garden."
But this still involves “from my possession” to “your possession”. I suppose that the phrase “possessiōne hortōrum” might be considered as a direct object here. As Hylander says I doubt Romans thought about grammar in this way.
I’m sure seneca doesn’t really mean that ““possessiōne hortōrum” might be considered as a direct object here.” Only in English translation is “the possession of a garden” that. The Latin construction is different.
To my way of thinking, only transitive verbs—verbs that can have direct objects—can have indirect objects. I’ve never understood why some grammar books (A&G appears to be one) want to allow intransitive verbs to have indirect objects. When there are so many labels to put on datives, many of them making unreal distinctions, why widen the simple precise definable category of “indirect object”?
locum ei cedere indirect obj., like locum ei dare; passive locus ei ceditur.
loco ei cedere dative of advantage, interest, or whatever else you want to call it, but not ind.obj.
Gratias tibi, mwh! Opinio tua mihi multum placuit! 
Exactly the way I sense it, being familiar with this idea in teaching (ancient and modern) Greek. Woodcock also defines as “indirect object” the dative complement of such monotransitive verbs (are they really mono-transitive? I consider them to be so perhaps influenced by the terminology in Greek; they are described as in-transitive in Latin, as you also have noted in your response), as placere, nocere, congruere, invidere etc. I have concluded that the term is used because these verbal arguments in dative never get passivized (: they never get the place of subject with a passive verb), unlike the Greek idiom, where for example ἐπιβουλεύω σοί becomes σύ ἐπιβουλεύῃ (ὑπ’ ἐμοῦ). With such verbs, in Latin only the (awkward) impersonal passive construction is availiable (e.g. noceo hominibus / nocetur hominibus (a me)).
But anyway, I have no problem undestanding the specific dative use, it is just a matter of (correct) terminology in teaching, especially when others than the actual teacher are going to examine a student. 
Thanks for your opinion, mwh!
Thanks mwh. I was trying to account for why someone might have concluded from JB Greenough that the ablative could be a direct object, which at first sight seems extraordinary. I can see that my “suppose” was too cryptic to be helpful. Anyway thanks for making it clear.