Meaning of Optative, Subjunctive; *-si in infinitives and 2nd sg. i

From: Andrew Jarrette
Message: 36673
Date: 2005-03-08

Anyone who has answered my emails will probably be aware that I rely on Andrew Sihler's New Comparative Grammar of Greek and Latin as a primary source of information about IE.  Though I count on it because of its thoroughness and frequent insights, I nevertheless have come across some rather weak points within it.
The first is the meaning (or translation) of the IE optative mood.  Throughout his book Andrew Sihler frequently translates IE optatives with the English conditional formant, e.g. he translates Gothic wiljau as "I would want", Greek dialectal ekselaunoia (an example of an exceptional optative formation) as "I would drive out", Homeric philoie: as "would love", and Homeric phoroie: as "would wear", among other similar examples, in addition to occasional translations as "I may love" (for philoie:n) and "I may hire out" (for misthoie:n).  Now is this translation of the optative by the English conditional correct?  Is this the meaning of the optative?  And is the other translation, the one indicating possibility ("I may love"), also correct?  I find that the function of the optative is difficult for me to understand - I know it is traditionally described as expressive of a wish or desire, but how does that become translated into normal English usage (should it be translated by the conditional?)?  Isn't a wish or desire expressed by desiderative forms, or by a verb such as *wel-, meaning "want (to)"?  And how does this relate to the translation of the optative by "may" (or, for that matter, "would", which I suspect is incorrect - the point of this letter)?  Also, what is the difference between optative and precative ("may he live to one hundred") -- isn't the precative also an expression of a wish or desire?
Furthermore, how does the optative differ from the subjunctive?  I am aware that in Germanic and Latin the former optative became what is termed the subjunctive, but was there any difference to begin with?  I find this area of terminology rather confusing, perhaps because English does not use its limited subjunctive in more than a few locutions, and often only in formal language -- thus I find the meaning of the subjunctive and optative difficult to identify because my language does not fully use them.  One source describes the subjunctive as indicative of requisition, but is that not the same as someone's wish?  I also find the description of the subjunctive as indicative of a future event anticipated with some doubt or reservation about its realization to be a rather hazy description - the reservation or doubt is usually effectively conveyed by the conjunction that precedes the subjunctive verb (such as unless, lest) or other introductory or preparatory words (e.g. Should you refuse this offer...) -- assuming that I am correct about the subjunctive being employed in such situations.  Is there really a need for a separate subjunctive conjugation?
The second weak point I observed in Sihler is that he says that the Latin infinitives in -ere (e.g. legere) are regularly derived from a form that ended with *-esi (*legesi), that the change of *-i to -e is regular, as is the rhotacism of *s.  But earlier in his work he says that the Latin 2nd sing. present active ending of these verbs, -is (e.g. legis) is from *-si (*legesi) with loss of the *-i.  Why does *legesi become legere in one instance, and legis in another?  Is there another explanation for the origin of Latin -ere?
One more question I forgot to mention in the "subject" line is, what is the meaning of the term "supine"?  How is it any different from the infinitive?
 
I hope someone can answer my questions, I would greatly appreciate a clarification of these issues.
 
Andrew Jarrette