A correspondent writes to report a school argument about whether a subject area should be capitalized or not. Is it: 'There'll be exams in History and Geography' or '... history and geography'? Opinion was split.
I'm not surprised. Capitalization is one of those areas very much subject to fashion and change. As Fowler once said, long ago, 'the use of capitals is largely governed by personal taste'. Some people overcapitalize; some undercapitalize.
It isn't usually a contentious issue when the reference is to a unique entity, such as an individual name. But generic notions always pose problems, and subject names fall into that category. Here, capitalization is primarily used either to draw special attention to a notion or to avoid ambiguity. An example of the latter would be: You'll find History on the third floor (ie the department) and You'll find history in the library (ie the subject). A capital is obligatory when talking about a specific notion, such as a course or exam paper, e.g. History 231.
But fashion always rules. For the past few years there's been a noticeable trend towards graphical simplicity - B.B.C. becoming BBC, and the like - and capitals have been affected. You'll find far more in newspapers of a few decades ago. And where there is an option, as in subject names, the trend has been to avoid caps. This is the advice of the main copy-editing style guides, and usage generally concurs, at present.