Legal Definitions - prohibited degree

A prohibited degree refers to a relationship between two individuals that is legally considered too close, either by blood (known as consanguinity) or by marriage (known as affinity), to permit them to enter into certain legal arrangements. Most commonly, this term applies to relationships that legally prevent people from marrying each other. Laws establishing prohibited degrees are designed to prevent incest, protect public health, and uphold societal norms regarding family relationships.

• Example 1: A man and his biological sister, both adults, decide they want to get married.

  Explanation: This relationship falls within a prohibited degree of consanguinity (blood relation) in virtually all legal systems. The law strictly forbids marriage between siblings due to the close genetic relationship and societal norms, making any such marriage legally invalid.

• Example 2: A woman seeks to marry her biological grandfather after he has been widowed.

  Explanation: This relationship is also within a prohibited degree of consanguinity, specifically a direct lineal relationship (grandparent and grandchild). Laws universally prohibit marriage between direct ancestors and descendants, regardless of their age or consent, to prevent incest and maintain family structure.

• Example 3: After a divorce, a man wishes to marry his former stepdaughter, who is now an adult.

  Explanation: Depending on the specific jurisdiction's laws, this relationship might still be considered within a prohibited degree by affinity (relationship through marriage), even though the marriage to the stepdaughter's mother has ended. Some legal systems maintain affinity prohibitions even after the marriage that created the relationship has dissolved, while others may allow it under certain conditions. This illustrates how "prohibited degree" can extend beyond blood relatives to relationships formed through marriage.