Source: p 268 Middle, Introducing Philosophy for Canadians: A Text with Integrated Readings (2011 1 ed).
Second, the theory doesn't satisfactorily explain what true beliefs correspond to. With what kind of thing or entity are they supposed to 'agree' or 'correspond'? To many philosophers, the answer has seemed obvious: true beliefs correspond to 'the facts'. But what, exactly, are facts? Here we need to be careful. Sometimes when we speak of 'facts', We are simply using that word as a synonym for truths, meaning 'true propositions or beliefs'. However. a defender of the correspondence theory had better not be using the word fact in this sense; for then all she would be saying is that true beliefs correspond to true beliefs— and that certainly isn't very helpful. Perhaps what is meant by fact is something like an actual state of affairs in the world, such as the cat being on the mat in the kitchen. This suggestion sounds more promising; but it, too, faces problems. For what are we to say about beliefs such as 'There is no cat on the mat', or 'There is no milk in the refrigerator', or 'I do not have a brother'?
If beliefs of this sort can be true — and they obviously can — doesn't this mean that there must be lots of shadowy 'negative' facts out there in the world, as well as positive ones?[...]
In the last sentence above, the use of the adjective 'shadowy' implies inferiority of negative facts compared to positive facts: is this true? Why? Does not their relative merit vary with the context? E.g., the negative fact that you have no disease (as told by your doctor), is good news to a patient.