 The first theory of such a semantic conception of information that was articulated in detail was Bar-Hillel and Carnap’s theory of semantic information. It is fitting then that we start here in  section 1.  In  section 1.1  we will see how the theory of semantic information has some consequences for certain types of statements, namely logical truths and contradictions, that many have found counterintuitive. In  section 1.2  we will see how Floridi responds to these problems, as well how others have extended and responded to Floridi’s proposal that we accept the veridicality thesis—that information be factive. A number of such responses are motivated by realist and naturalist considerations with regard to the ontology of semantic information. In  section 2  we will look at semantic conceptions of information that take naturalist metaphysics seriously. Here we will see how Fodor, Dretske, Evans, Lewis, Recanati, and Jackson propose and defend semantic conceptions of information that turn on modes of presentation, and that are broadly naturalist insofar as they attempt to subsume information within causal relations of various sorts. Any causal theory of meaning or knowledge will face the problem of accounting for the meaning of, and our epistemic access to, abstract objects.