Sicut humanae animae est quidam habitus naturalis quo principia speculativarum scientiarum cognoscit, quem vocamus intellectum principiorum; ita etiam in ea est quidam habitus naturalis primorum principiorum operabilium, quae sunt universalia principia iuris naturalis; qui quidem habitus ad synderesim pertinet.
"Just as there is a natural habitude in the human soul by which it knows the principles of the speculative sciences, which we call understanding of principles, so also there is in it a natural habitude for the first principles of do-able things, which are the universal principles of natural law; which habitude pertains to synderesis."
De veritate q. 16 art. 1
