We present the new paradigm of logic file systems, its implementation, and first experimental results. It offers in an integrated way navigation and classification, the possibility of expressive queries, ease of use, and possible heterogeneity of data. This paradigm is object-centered. It associates logical descriptions to objects, and logical relations between descriptions serve as a basis for navigation and querying. We compare logic file systems with the hierarchical, boolean, and data-base paradigms. We present briefly the rôle of logic in logic file systems, and in more details the implementation issues of a particular logic file system that uses a simple logic.