Broadly speaking there are three general millennial systems of thought, each professing to set forth true Biblical eschatology - a study of events that were future at the time they were predicted. These systems of thought are premillennialism, postmillennialism, and amillennialism. In addition to these three broad views, there are distinct variations within each system which can be of major significance. In spite of differences, there are also important similarities which the various millennial systems should hold in common.