The marital confusion of Robert Burns and Jean Armour may seem strange to us, in a day when weddings are held on a pre-announced date and recorded in government records. That Robert and Jean could be legally married three times and still not be sure when or if they were married is baffling unless you know the marriage laws of the time.
Scotland had law centuries before it had lawyers and relied on a clan system of judgement rather than the British system of written law and precedents. In fact, when Cromwell's lawyers came to Scotland, they were referred to as "kinless loons" -- how could they dispense justice if they weren't even related to the parties? It was a different kind of thinking.
In Burns's time, there were three forms of "irregular" (but nevertheless legal) marriage:
1) Declaration de praesenti referred to as "marriage in the Scotch fashion." If by word or written proof a man said he married a woman, then they were legally married and all children were legitimate. This did not have to be done in front of witnesses. This was done when a couple was in love and wanted to consummate the marraige, but the man was not in a financial condition to support the woman or provide a house for them to live in. Robert Burns gave Jean Armour such a paper when she was pregnant; he could not provide them with a home and couldn't ask his mother and brothers to support another live-in person. The problem with this kind of marriage is that there are no witnesses -- and later the marriage can be denied if circumstances change. Robert and Jean, of course, abused this in the worst way. When Jean's father tore up the paper, the marriage was still valid. But Jean considered herself single. She was shamed in the church for "fornication", which meant the church also considered her unmarried. She then moved to another city and took up with an old boyfriend. Burns, meanwhile, received a certficate of batchelorhood from the parish, which considered him single, and proposed to Highland Mary and other women in the meantime. This kind of marriage was made illegal by the Marriage (Scotland) Act of 1939 and was no longer legal after the Act came into force on July 1 1940.
2) Promissio subsequente copula meant that when a couple engaged in sexual intercourse but intended to marry at a later date, the engagement then became a legal marraige. This dates back to Canon law in the Middle Ages and was necessary at a time when there was not a priest to perform marraiges except at infrequent intervals. It was legal, but the curch often frowned upon it, again because it could be abused and the marriage denied later. Robert and Jean did not have this type of marraige. When he got back together with Jean, even when she was pregnant with the second set of twins, he emphasized that if she ever spoke of marriage, he would leave her.
3) Marriage by Habit and Repute was originally meant to protect widows from being denied benefits if they could not prove their marriage. Regardless of accusations that there was no marriage, if the man and woman lived together as husband and wife "by habit and repute", then it was also a marriage in law. Again, this is a law which started out as a protection and later became an abuse. Robert and Jean did not have this type of marriage; in fact, they did not live together even after their (second) marriage, but commuted to their farm house while the construction was being finished. It was during this time that Burns discovered what a hard worker and agreeable companion Jean really was.
While promissio subsequent copula was also outlawed by the Marriage Act of 1939, the third form, that living together by habit and repute implied consent, was never addressed. Perhaps it had died out on its own or perhaps it had ceased to be considered a form of marriage.
A nineteenth century Tourist's Matrimonial Guide Through Scotland, commented on declaration de praesenti:
What's important, of course, is that Robert and Jean did finally get married (three times!) and have a marriage that was satisfactory to both of them. It was a long, torturous, complicated journey, but once completed, both seemed happy and never considered parting again.
Walker, David M. The Scottish Legal System. (Edinburgh: W. Green and Son, Ltd, 1963) (UWM Call No. KJC .W35x)
Thomas Breun Smith. Scotland: Development of Its Laws and Constitution. (London: Stevens and Sons, 1962) (UWM Call No. KJC .S6)
The Stair Society. An Introduction to Scottish Legal History. (Alva: Robert Cunningham and Sons, Ltd, 1958) (UWM Call No. KJC .S71x)