“philanthropy” as an uncountable noun

Solution 1:

I believe the uncountable definition is referring to the concept (an abstraction or metaphysical postulation); i.e. neither a specific act, nor a specific mental state. An act of philanthropy is a demonstration of the concept. In the absence of an action or an actor (one to attribute the mental state to), the concept still remains.

I would draw an analogy to “Love”. One may exhibit love, and one my experience love. But in the absence of an actor or an act, the concept of love remains; e.g. “Love is in the air”, in this usage love is an intangible and innumerable concept.

LINK: Conceptual example as to the abstract usage of Love

Looking to the Philosophy of Plato, Philanthropy, as to the definition the OP question looks to understand, is a “Form”. Experience (the mental-state), action, and observation (phenomena) are all metaphorical “shadows” of the ethereal Forms that underlie “reality”. These issues are still debated in the philosophical field of Metaphysics.

LINK: Plato Theory of Form by Erica Cummings

Solution 2:

It means both, and sometimes it is difficult to determine which is meant, or if there is a real distinction.

Some other character traits which have characteristic behaviours have the same ambiguity, eg: generosity, stinginess. Others do not seem to.