Full Idea
The Anti-Razor says 'whenever an affirmative proposition is truly stated, if one thing does not suffice to account for its truth, then one must posit things, and if two do not suffice then three, and so on to infinity'.
Gist of Idea
Anti-Razor: if you can't account for a truth, keep positing things until you can
Source
Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 14.3)
Book Reference
Pasnau,Robert: 'Metaphysical Themes 1274-1671' [OUP 2011], p.291
A Reaction
This is quoted from an anonymous logic text of 1325. Apparently Ockham himself articulated the idea more than once.