(Lat., well-founded phenomena) The phrase is especially associated with Leibniz . Any created monad's perceptions or phenomena will be more or less confused. But some correspond to composite substances, or monads connected by a substantial chain. These are the phenomena bene fundata that give rise to what we call information about an external world. Perceptions of ordinary objects or even rainbows fall into this class, as opposed to dreams and hallucinations.
Philosophy dictionary. Academic. 2011.