The Concepts of Consanguinity & Affinity
in Roman Catholic Marriage Records
This is part of an article that I originally wrote for the Island Register. My thanks to Dave Hunter, owner of the Island Register, for allowing me to modify and integrate his original code rather than having to redo this all from scratch!
This article was also published in Issue #93 of the American-Canadian Genealogist, the quarterly journal of the American-Canadian Genealogical Society.
Relationships, through either blood (consanguinity) or marriage (affinity) were recorded, and marriage dispensations were granted, by "degree". A first degree relationship would indicate siblings; a second degree relationship would indicate first cousins; third degree meant second cousins; and fourth degree indicated third cousins. Relationships more distant than third cousins (fourth degree) were not recorded in the marriage records. You can think of it this way: brothers and sisters were one degree, or one generation, away from the common ancestor; first cousins were two generations away from the common ancestor; etc.
Naturally, marriages to the first degree were never permitted, by either civil or canon law.
Removals could also be recorded, so that a marriage to a second cousin once removed would receive a dispensation of the "third to fourth" or "third and fourth" degree. I have not seen an instance where two or more degrees of removal (i.e.: second cousin twice removed) was ever noted.
If a couple was related as second cousin only once, the dispensation might be recorded as "third degree", "third degree simple", or "third degree pure". If they were related as second cousin twice (through two separate lines), the dispensation might be recorded as "third degree double" or "third degree on one side and third degree on the other side", etc.
Dispensations of affinity were treated in the same manner as dispensations of consanguinity. Effectively, once you were married, your wife's blood relatives would be considered to have the same relationship to you as if they were actually blood relatives to you as well. So, if a widowed man decided to marry his late wife's first cousin, the couple would receive a dispensation to the second degree. The only difference is that it would be a dispensation of affinity rather than a dispensation of consanguinity (unless, of course, a true blood relationship also existed, and that would be noted as well).
One important item to note is how half-relationships and step-relationships were treated. Half-relationships would fall under the category of consanguinity, since the people involved were still blood relatives, even though they shared only one common ancestor rather than two. However, a step-relationship would fall into the category of affinity, since the common point between the two families was a result of marriage rather than blood ties.
The priests were supposed to record all relationships of the fourth degree and closer - so, a couple who were related in four different ways should have received four different dispensations. Unfortunately, this was not always done. As well, each priest used slightly different terminology in their records - it might take some practice to figure out exactly what each priest meant. The best thing to do is to trace out some dispensations, where the lineages are known from other sources, to determine that particular priest's terminology and accuracy. The accuracy depended on two things: the priest's desire to get it both right and complete; and the couple's accuracy in recalling and reciting their own lineages (garbage in- garbage out!). Like anything else in genealogy, one must never take anything for granted.
Unfortunately, not all of the priests actually made the effort to determine whether or not a couple was related. So, some couples who should have received dispensations didn't. This is very unfortunate since marriage dispensations can prove to be very useful to genealogists in tracing and sorting out their family trees. Where gaps exist in the records (as occurs on PEI), the dispensations might be the only manner of tracing certain families. This is especially true for the Acadian families, since large gaps in the records exist from the time of the expulsion. It is also helpful for immigrant families as we might not have any indication of connections between families after they arrived in North America. But, the dispensations might show that these otherwise un-related families did indeed have some blood connections back in the Old World.
This is not necessarily an easy subject to address, and I will not claim to be an expert on the matter. I do hope that I have provided some explanation to your question. And, I welcome any comments from others who might have more knowledge of, or more experience with, marriage dispensations.