Full Idea
The most powerful arguments establishing substantial forms are based on the necessity, for the perfect constitution of a natural being, that all the faculties and operations of that being are rooted in one essential principle.
Gist of Idea
The best support for substantial forms is the co-ordinated unity of a natural being
Source
Francisco Suárez (Disputationes metaphysicae [1597], 15.10.64), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 24.4
Book Reference
Pasnau,Robert: 'Metaphysical Themes 1274-1671' [OUP 2011], p.561
A Reaction
Note Idea 15756, that this stability not only applies to biological entities (the usual Aristotelian examples), but also to non-living natural kinds. We might say that the drive for survival is someone united around a single entity.
Related Idea
Idea 15756 Some truths are not because of a thing's properties, but because of the properties of related things [Shoemaker]