Questions form a large part of the educative process. Teachers ask a lot of questions and are asked many in turn. Most of the questions are welcomed, but the one in the title never falls into this category. I have never answered the question with a straight 'no' (I tend to employ my best withering stare), but I wonder what the response to this answer would be? To pack up one's books and leave? To tune out until the material becomes more relevant?
What the pupil is really asking is whether they are likely to be directly questioned on this material in an examination. This implies that all knowledge can be categorised as necessary or unnecessary. The necessary stuff is to be found on the GCSE or A level syllabus, and the unnecessary stuff, well, that's simply unnecessary. Why would you ever want to know anything that you weren't going to be tested on?
Examinations are important, or at least doing well in examinations is important, but examinations are best seen as a celebration of all knowledge gained up to that point. The examination syllabus guides the teaching and revision process, and in the run-up to examinations, it becomes an almost biblical document. But for most of the educative process, we do not find ourselves in the run-up to public examinations, and it is important to realise that not all great literature is to be found in the GCSE English syllabus and one cannot find all that is worth knowing about philosophy and ethics in the GCSE RS syllabus.
Teachers tend to blame the syllabus and to use it as a crutch in roughly equal measure. If the pupils aren't finding the work interesting, laying the blame at the door of the syllabus is a standard strategy: 'we have to get through this, it's in the syllabus'. Highlighting work that 'comes up on the exam all the time' is another tried and tested method to perk up the reluctant learner. I do think it's important for pupils to know why one topic leads on to another and to be aware of how the subject is structured, but this shouldn't be done simply because section 3.1a of the syllabus leads into section 3.1b. I wonder how many Lower Sixth lessons go by before exams, coursework, modules and syllabus are mentioned?
A simple philosophy for all Sixth Form teachers is this: you have two years to allow pupils to become the best Physicists/Historians/Hispanists they can be, and at the end of this time, you need to assiduously prepare these pupils for the examinations that will allow them to access the Higher Education institution of their choice.
Going back to the concept of necessary and unnecessary knowledge, can it be argued that any knowledge is unnecessary? After all, even the most trivial fact might help you win some money in a pub quiz. But it's far more than that, and I firmly believe that knowledge enhances your life. Knowledge of the painter El Greco makes a visit to Toledo far richer; driving large distances when in the US is more pleasurable having read works by Kerouac and Steinbeck; knowledge of the Hillsborough disaster makes the recent Liverpool surge to the title far more poignant. None of this knowledge will ever help you pass an examination, but without them, Toledo is simply a pretty town, a long drive in the US is simply necessary to get from A to B and Hillsborough is just a football stadium in Sheffield. Knowledge means interest, knowledge means context and (in some cases) knowledge means power.
Absence of knowledge can never be a good thing; this point I feel is unarguable and some fault must lie with the approach taken by teachers. 'Extra' knowledge, that is knowledge beyond the confines of the syllabus, is too often seen as being the privilege of the academically able, with academic extension something that is laid on for the scholars, the bright and the interested. Of course this is not true; academic extension is for everyone, though it is inevitable that the nature of that extension will differ from pupil to pupil. It is fundamentally wrong that any pupil should fail to interact with material that raises them from the bare bones of a subject. A certain academic liberation exists when learning is done for its own sake. Improving one's knowledge is an enjoyable process and in turn this leads to greater enjoyment of the world around us. We need to get away from the mentality that all learning is simply a means to an end; I often hear pupils stating that they 'have to read this book as part of preparation for Oxbridge'. If this is literally true, and it is simply being read for some necessary progression up the academic ladder, is the enjoyment of the book not removed, or at least seriously diminished?
And just to be clear, if any doubt remains: yes, you really do need to know this.