This view of knowledge as relatively isolated fields is the one most widely shared by both educators and non-educators. There are, however, dissident voices.
Some educators—interdisciplinarians—point out that, in the real world, the things we're trying to understand almost never fall into neat little compartments that correspond to the disciplines. They look for ways to bridge between the disciplines, and for disciplinary parallels and intersections.
Other educators say the disciplines shouldn't be seen as ends in themselves but as tools. They start with a social problem, topic, or theme and bring the disciplines to bear on it, examining it from different disciplinary perspectives.
Still others never actually mention or even credit the disciplines, but use them nevertheless as sources of facts, ideas or insights as they attempt to help students understand themselves, their immediate experience, or historical events and conditions.
Even the dissidents, then, assume that the disciplines are the foundation of the curriculum, assume that they disassemble the reality we're trying to understand in the most useful and logical way.
It's an erroneous assumption.
The disciplines certainly have their uses. We've created a society that can't function without highly specialized knowledge, and the disciplines provide that. But they aren't by any means the most useful or logical way to organize the general education curriculum. What students need is a "mental filing system" organizing and making accessible in memory everything they know, a system that helps them distinguish between the important and the trivial, a system that suggests to them things they could know but don't, a system that makes clear the systemically integrated, mutually supportive nature of knowledge, a system that shows them the basic processes by means of which knowledge expands. And the system should do all of these things in ways the average adolescent can understand and explain.
None of this is possible if the curriculum is based on the academic disciplines. It isn't possible because neither individually nor collectively are those disciplines a "system." They took shape at different times, have different aims, deal with different content, use different vocabularies, employ different conceptual frameworks, ignore vast areas of important knowledge, and operate at different levels of generality. They can't be integrated, but even if they could be integrated, the result would be intellectually unmanageable by even the best of students.
The "mini" conceptual frameworks provided by the familiar disciplines do a job that needs doing, but they leave undone something central to an acceptable general education curriculum. They don't show students the whole of which the disciplines are random parts, a whole which is much greater than the sum of those parts.