A Rabbi named Peter?
We find several Tosafists (“Ba’alei Tosafos”) with peculiar names, the most surprising being, perhaps, “Rabbenu Peter”, see Tosafos Gittin 8a. Needless to say, Peter is not a Jewish name.
Although it is true that many Rishonim had additional secular names for legal and other reasons, it is not likely these would be mentioned in their own Torah books, unwarranted and unrequired. Here, the convention is to mention the ‘religious’ Hebrew name throughout the book (and often the patronymic name on the title page). Most Tosafists are, in fact, identified by their Hebrew names, either in full or in acronyms. Take Rabbi Yitzchak (Ri), Rabbi Shimon ben Meir (Rashbam), Rabbi Moshe (Haram), etc.
Several Poskim have discussed the name Peter as regards the laws of names in Gittin (Jewish Divorce) based on this Tosafos. They (tentatively) wish to establish the name as a legally Jewish one in this respect. No, not any assimilated Peter, but anyone hypothetically named after this Rabbi would be written on a Get as פטר; not פעט(ע)ר!
I once heard a better explanation from Rabbi Yechiel Sternberg, chief editor of Yeshurun, a well-regarded Torah journal. He noted there are also Rabbenu Tam, Rabbi Yosef Bechor Shor, Rabbi Porat, and probably others, none of whom are referred to by their real name.
It is therefore quite likely that Rabbenu “Peter”, too, is merely a “Term of Endearment” for a Tosafist who was a firstborn as per Exodus 34:19 see Rashi ad. loc. and Numbers 3:12). He also mentioned another option I can’t remember. Either way, his name is not to be enunciated as “Pea-ter” but as “Pet-ehr”. פטר is no name at all, just a nickname.
Now let’s get back to the other Tosafists (I’m sure you all know the rest, but still).
“Rabbenu Tam” is known to be a reference to Rabbi Yaakov, a grandson of Rashi and uncle to Ri the Elder, c.f. Tosafos sub voce “Amar” Beitza 17b.
I once read a theory that this title is a reference to the story in Tosafos Kesubos 47b where he “neutralized” the interpretation of “Vetam Larik Kochachem”. In my opinion, this is unlikely. Had this been true, that same Tosafos would have mentioned as much.
The standard explanation for the nickname is this verse describing his biblical namesake Jacob —
ויעקב איש תם ישב אהלים
In this context, “Tam” means either “perfect” or “innocent”, an honorific deemed to fit Rashi’s esteemed grandson.
By the way, Rabbenu Tam is not the only Tosafist named Yaakov. Another is Rabbi Yaakov of Orleans, c.f. Tosafos Pesachim beginning of 8b (and many other places). In the recently published Tosafos on Shabbos there is a “new” Tosafist called simply “Tam” (not to be confused with Tom!). His first name must have been Yaakov too!
As for Rabbi Yosef “Bechor Shor”, here both the true name and the nickname are recorded together. Note Tosafos s.v. “Tevuos” Sanhedrin 42a, that “Bechor Shor” is an allusion to Yosef. Go on; tell us your own theory for the reference!
“Rabbi Porat”, too, must be a Yosef, just as the “original” Joseph was called (Genesis 49:22) —
בן פרת יוסף בן פרת עלי עין
(“Porat” here means charm or glory, check commentaries ad. loc.)
Tosafos Nazir 10a s.v. “Parah” quotes a “Rabbi, Rabbenu Yosef”, and Tosafos ibid. 37b s.v. “Migi’ulei” mentions a Rabbi Yossi, both from Jerusalem. A certain modern author wonders how come two Tosafists both termed Joseph were living in Jerusalem at a time when not many Jews at all were located in Israel. Legally speaking, Yosef and Yosi are definitely not the same name, nor is Yossi the truncated form of Yosef.
Ah, but could ‘Yossi’ be merely a nickname for Yosef?
This train of thought solves an additional problem as well. Various scholars have wondered at our newfound ‘Custom’ of giving compound names. Some have tried to point out the Tosafist “Rabbi Yaakov Israel” as evidence of this being somewhat common even before our time (see Tosafos s.v. “Hani” Chulin 112a). Then again, who is to say this is not simply another example of Tosafists receiving “pet names”?
Maybe his real name is either “Yaakov” or “Israel”, and his title became “Rabbi Yaakov Israel” as a reminder of the verse in which our forefather Jacob had an alternative name gifted him by an angel he defeated, see Genesis 32:29 —
ויאמר לא יעקב יאמר עוד שמך כי אם ישראל
(Perhaps Rabbi Y. won a fearsome battle…)
Clearly, some of this is mere speculation, but the point here is not to decide matters but to avoid a decision, showing how they might also be resolved without reaching newfound Halachic (and quasi-Halachic) conclusions.
This post is not just for those few editors doing work on the Tosafos, but to remind us of something we often forget. Just like when using logic to reach Halachic conclusions, attempting to learn Halacha from history, too, must be done carefully and painstakingly. Yes, this is an extreme example, but the point is still valid.
P.S. I am very well aware there is more to be said on several of the issues addressed in this post.