Full Idea
I believe that both Boyle and Locke were suspicious of forces, regarding them as occult.
Clarification
'occult' means they are mystical nonsense
Gist of Idea
Boyle and Locke suspect forces of being occult
Source
report of John Locke (Essay Conc Human Understanding (2nd Ed) [1694]) by Peter Alexander - Ideas, Qualities and Corpuscles 7
Book Reference
Alexander,Peter: 'Ideas, Qualities and Corpuscles' [CUP 1985], p.163
A Reaction
I take this to be key difference between these two and Leibniz, with the latter on the side of the angels.