One theory has it that the fourth finger of the left hand was used because it was thought to hold a vein connecting directly to the heart.
- The fourth finger of the left hand.
- ^ 1855, Charles Edwards, The History and Poetry of Finger-Rings, p206 — We have remarked on the vulgar error of a vein going from the fourth finger of the left hand to the heart. It is said by Swinburn and others that therefore it became the wedding finger. The priesthood kept up this idea by still keeping it as the wedding finger ; but it was got at through the use of the Trinity...