Each of the core disciplines has its role to play in the building up of the whole and each has its own more specific set of objectives for the different stages at which it is being taught. Quite simply, at each stage there are things we want children to know, things they ought to be able to do, and habits, dispositions or aptitudes they ought to have acquired or be acquiring. Considering these in detail and in light of the general objectives of each subject, and considering each subject in light of the overall end, teachers in specific subjects and at specific stages can see how each stage builds upon the previous stage, how their work contributes to the "finished product" and how they can tailor specific classes and methods to serve these ideals more effectively.