Verb forms after "tamquam si"

Question

In Suetonius's Vita Horati, a letter from Augustus to Horace is quoted, which includes the sentence:

Sume tibi aliquid iuris apud me, tamquam si convictor mihi fueris.

The Loeb translation gives: "Enjoy any privilege at my house, as if you were making your home there".

Why the perfect subjunctive fueris?

Bennett's New Latin Grammar, section 307, discusses the forms of verbs after such phrases as tamquam si:

Conditional Clauses of Comparison are introduced by the particles, ac sī, ut sī, quasi, quam sī, tamquam sī, velut sī, or simply by velut or tamquam. They stand in the Subjunctive mood and regularly involve an ellipsis (see § 374, 1), as indicated in the following examples:—
tantus patrēs metus cēpit, velat sī jam ad portās hostis esset, as great fear seized the senators as (would have seized them) if the enemy were already at the gates; sed quid ego hīs testibus ūtor quasi rēs dubia aut obscūra sit, but why do I use these witnesses, as (I should do) if the matter were doubtful or obscure; serviam tibi tam quasi ēmerīs mē argentō, I will serve you as though you had bought me for money.

Note that in sentences of this kind the Latin observes the regular principles for the Sequence of Tenses. Thus after principal tenses the Latin uses the Present and Perfect (as in the second and third examples), where the English uses the Past and Past Perfect.

Now, in this example we're in primary sequence. So if the usual sequence of tenses rules are in force, the perfect subjunctive should express prior time: "as if you had (at some time in the past) been living with me". This seems not to be what's intended, though – rather, it looks like a present counterfactual: "as if you were (now) living with me". But in that case, shouldn't we expect either sis (if following sequence of tenses), or maybe esses (as in an ordinary present counterfactual condition)?

As a bonus question, how does the Loeb get to "enjoy any privilege at my house"? AFAIK, aliquis does not mean "any whatsoever" (that's quicumque or quilibet), but "some", so it should literally be "take some (not further identified) kind of privilege at my house".

Answer 1

It possible to read the sentence with fueris having a perfect meaning: "… as if you had dined with me." I read the idea roughly like "I have accepted you as a guest in my house in the past, and therefore my home is yours". Convictor can mean someone who lives together, but also "table companion" and "familiar friend" are suggested in L&S.

Based on your answer to my question (and the Oxford Latin Syntax), it would also make sense to read the perfect conjunctive with a present meaning. OLS (p. 493) says that "the perfect subjunctive forms are supposed to be milder or less direct than the present ones" without implying a temporal difference. The next sentence says that this is but an unsupported theory, but it seems that we do not have a conclusive explanation at all to the perfect conjunctive in a present meaning.

In either case, I don't think tamquam si has any special effect here.

As for the bonus question, aliquis seems to have a much broader set of meanings than you assume. Depending on context, it can mean "anything (whatsoever)" or "some" or other things. (There does not seem to be a clear correspondence between Latin and English pronouns apart from first and second person personal ones.) To quote L&S:

aliquis, more emphatic than quis, denotes that an object really exists, but that nothing depends upon its individuality; no matter of what kind it may be, if it is only one, and not none

I agree with Loeb that the most natural English translation is "any" in this case.