What is the case in favour of adelphopoiesis as a relationship akin to marriage?

Boswell was the first to make the case that adelphopoiesis was a form of civil union, but his study has been subject to harsh criticism since it's publication as a work that attempts to re-write history by making claims that the practice of adelphopoiesis was h*m*sexual in nature.

Adelphopoiesis (from the Greek: ἀδελφοποίησις, derived from ἀδελφός (adelphos) "brother" and ποιέω (poieō) "make" - literally "brother-making") is still practiced today in the Syrian Orthodox Church as a ceremony that joins two unrelated men as brothers (or two women as sisters, since in the Greek compound, the word adelpho- can signify either noun).

Robin Darling Young, an associate professor of spirituality at the Catholic University of America, gives this account of her union to her colleague Professor Susan Ashbrook Harvey of Brown University by a Syrian Orthodox archbishop from St. Mark's Monastery in Jerusalem:

"...the bishop had us join our right hands together and he wrapped them in a portion of his garment. He pronounced a series of prayers over us, told us that we were united as sisters, and admonished us not to quarrel. Ours was a sisterhood stronger than blood, confirmed in the outpouring of the Holy Spirit, he said, and since it was a spiritual union, it would last beyond the grave."

It is important to note that both women had husbands. Adelphopoiesis is a form of adoption, uniting two people of the same-sex as spiritual brothers or sisters, it is distinct from marriage as is evidenced by Professor Young's and Harvey's union, they had a "same-sex union", but were both already married to men. Professor Young gives her account of her union, as well as her argument against John Boswell's interpretation of adelphopoiesis in her article, "Gay Marriage: Reimagining Church History."

John Boswell was a h*m*sexual, as a historian and professor he focused his studies on the issue of Christianity and h*m*sexuality. Boswell translated the word adelphopoiesis as "same-sex union", claiming that there were problems with accurately translating Ancient Greek and Latin terms regarding love, relationships, and unions into English, and argues that the Latin term for "brother" was a euphemism for "lover". Although his translation of the word is not necessarily inaccurate—since adelpho can signify either brother or sister—his translation gets, "lost in translation" in modern culture as the term, "same-sex union" is almost always associated with same-sex marriage in today's society.

In his book, "Same-Sex Unions in Pre-Modern Europe", which was released the same year that Boswell died from AIDS, he takes a very systematic and careful approach to building his conclusion, but takes translations and practices very much out of context by relating them to modern circumstances. Writing the history of a reli­gious institution involves under­standing concepts and language within their historical and cultural context. Otherwise, the risk is taken that history will be rewritten to suit current preoccupations.

Simply put, adelphopoiesis was certainly a kind of union between two individuals, but to make a case in favor of adelphopoiesis as a form of civil union, in the sense of making this institution equivalent to matri­mony, necessitates a perspective and context foreign to the ancient Church.

I have not read Boswell's book, but I have found a number of reviews of it online (1 2 3).

Based on the reviews, Boswell's argument seems to be threefold.

Marriage

First, he points out that the definition of marriage has changed over the centuries. Even today there are different kinds of marriage. A couple can get a civil marriage (performed by a judge) or a religious marriage (performed by ordained clergy). In some countries a clergy person is authorized to sign the legal paperwork so that one ceremony can satisfy both God and the law. In some locations, common-law marriage (a tradition going back to ancient times) is an option allowing a couple to get married without a ceremony.

In many places today a married person cannot marry anyone else without breaking their current contract (and even then, some churches would not allow a second marriage), but in ancient times polygamy was much more widely practiced. Solomon was said to have 700 wives (and also 300 concubines, which was somewhat akin to marriage but was a different type of relationship.)

Yet another type of marital relationship in ancient times was that of Greek soldiers, who were encouraged to pair up--the reasoning being that when they went into battle they would be fighting alongside their lovers, and would therefore fight more valiantly.

On the other end of the spectrum, many early Christians took a view (following Paul's logic in 1 Corinthians 7 to its extreme conclusion) that abstinence was preferable to sexual activity even within a marriage, as far as it was possible.

So Boswell cautions that we can't necessarily take 20th century (well, 21st century, now) preconceptions of marriage and assume that marriage was always like this.

Brothers

Second, Boswell argues that the word adelphopoiesis (literally, "brother-making") was a euphemism for a ceremony analogous to a heterosexual marriage. He notes similarities; for example, the adelphopoiesis ceremony often included hand holding and a kiss, and concluded with a shared communion celebration. (The reviewers also note that there are differences, but don't elaborate.)

Certainly, the term is not intended literally. As one reviewer notes, only your parents can literally make a brother for you. But how it was generally understood by those who took part in adelphopoiesis ceremonies, we can't be entirely sure.

Opposition

Finally, Boswell notes that both the church and the state began to take a stronger stance against h*m*sexual behavior beginning in the 13th century. Boswell quotes 16th century philosopher Michel de Montaigne, who witnessed an adelphopoiesis ceremony: "...the Church of Saint John of the Latin Gate, in which some Portuguese some years before had entered into a strange 'brotherhood.' Two males married each other at Mass, with the same ceremonies we use for our marriages, taking Communion together, using the same nuptial Scripture, after which they slept and ate together." Civil authorities, alerted by Montaigne's essay, arrested and punished participants in the ceremony.

By the end of that century adelphopoiesis was banned throughout Europe. The doucments describing it were locked away, and in at least one case, the pages containing the adelphopoiesis ceremony were ripped from the book.

Summary

In summary, marriage has had many different meanings. So, too, "brotherhood" has another meaning. (But what is it?) Finally, adelphopoiesis was eventually banned by authorities.

Most scholars don't believe Boswell's case is very strong. It does appear that the adelphopoiesis ceremony may have, in the eyes of some couples, been seen as akin to marriage, but there's no clear evidence it was ever viewed that way by the church.