Wikipedia claims, "It is possible that the kenosis passage in Philippians 2:5-11 may have been a Christian hymn that Paul quoted." If Paul is possibly not the author of this hymn, is there any evidence of the original author? All I've been able to find so far is that Stephen is a possible candidate; but I'm not sure what arguments are made for that position.
The passage in question is Philippians 2:5-11 (NET Bible):
You should have the same attitude toward one another that Christ Jesus had,
who though he existed in the form of God did not regard equality with God as something to be grasped, but emptied himself by taking on the form of a slave, by looking like other men, and by sharing in human nature. He humbled himself, by becoming obedient to the point of death – even death on a cross! As a result God exalted him and gave him the name that is above every name, so that at the name of Jesus every knee will bow – in heaven and on earth and under the earth – and every tongue confess that Jesus Christ is Lord to the glory of God the Father.
The NET Bible note on the typesetting reads:
This passage has been typeset as poetry because many scholars regard this passage as poetic or hymnic. These terms are used broadly to refer to the genre of writing, not to the content. There are two broad criteria for determining if a passage is poetic or hymnic: “(a) stylistic: a certain rhythmical lilt when the passages are read aloud, the presence of parallelismus membrorum (i.e., an arrangement into couplets), the semblance of some metre, and the presence of rhetorical devices such as alliteration, chiasmus, and antithesis; and (b) linguistic: an unusual vocabulary, particularly the presence of theological terms, which is different from the surrounding context” (P. T. O’Brien, Philippians [NIGTC], 188-89). Classifying a passage as hymnic or poetic is important because understanding this genre can provide keys to interpretation. However, not all scholars agree that the above criteria are present in this passage, so the decision to typeset it as poetry should be viewed as a tentative decision about its genre.
To me, the section looks very much like poetry and, if so, a song (or hymn). It's a compact and rhythmic summary of a complex idea. It's a passage to be memorized both because of the theological import and the flow of the words. (For instance, the repeated use of the word "name" in verses 9 and 10.)
Music has been a part of Christianity from the beginning Mark 14:26 (ESV):
And when they had sung a hymn, they went out to the Mount of Olives.
Presumably hymns at that stage were composed much like modern song: a literarily-gifted person wrote the words and a musically-gifted person (perhaps the same person) wrote the music. With use, the words were likely to have changed to smooth out rough edges and fit more appropriately with the music. Hymns were certainly an oral tradition and rarely written down.
If it is a hymn, Paul probably would have expected the Philippians to be familiar with it or he would certainly have used his own words.
I haven't found a source that quotes the hymn separately from Paul. Origen directly attributed the passage to Paul:
[It] is sufficient at present to quote one testimony of Paul to the following effect: “Let this mind be in you which was also in Christ Jesus; who, being in the form of God, thought it not robbery to be equal with God, but made Himself of no reputation, and took upon Him the form of a servant, and was made in the likeness of men; and being found in fashion as a man, He humbled Himself, and became obedient unto death, even the death of the cross. Wherefore God also hath highly exalted Him, and given Him a name which is above every name.”
It's interesting that he pulls out the passage in its entirety to make his point, but he doesn't call the section a hymn or suggest that it has a history before Paul.
Since Paul doesn't identify his source (or even designate the section as a hymn), anything we might say about the passage's author would be speculative at best. If Stephen has been identified as the author, it's likely to be wishful thinking more than any solid history. The only reliable source of the hymn is Paul and we can't trace it further back.
Worth noting that in Acts 16, when Paul and Silas are in PHILIPPI (the place this letter is addressed to), he and Silas, though Roman citizens (= "in the form of God") are flogged and then put in prison ("emptied themselves"). They spend the evening in prison "singing HYMNS to God." Having taken this humility upon themselves in submission to God, they are then "Exalted" (their fetters fall off), and they are released! Sounds a bit like the Christ Hymn, and well, it was in Phillipi that this happens. Seems like Paul or Silas might be a good candidate for the composer of the hymn, which they then taught to the Phillipians, and the later quoted to them as something they would recognize in this letter. The pattern "imitate me as I imitate Christ" and "I imitate Christ in his suffering, so that I can like him be resurrected" is ALL OVER the place in Paul, but particularly in Philippians (1:29-30; 3:17;4:9 etc.). In other words, it is not at all out of the picture that Paul, in his humiliating imprisonment and later release for Christ, saw his own life as being patterned on the suffering and exaltation of Christ.