Full Idea
The Major Real distinction is if A can exist in the real order without B, and B can exist in the real order without A.
Gist of Idea
Major Real distinction: A and B have independent existences
Source
report of Francisco Suárez (Disputationes metaphysicae [1597], Bk VII) by Stephen Boulter - Why Medieval Philosophy Matters 4
Book Reference
Boulter,Stephen: 'Why Medieval Philosophy Matters' [Bloomsbury 2019], p.97
A Reaction
Boulter's example is the distinction between Peter and Paul, where their identity of kind is irrelevant. This is two-way independence.