Hello Nigel.
You raise a very good point, this is one of the evils of our
education system.
I'm not an expert on this by any means. But I took the liberty of
transposing your letter to the British Humanist Association member's
discussion group and asking for ideas.
The responses suggested that you should approach the head again, and
complain about the non inclusive nature of the harvest festival.
After all, it's not just atheists who would be offended by the
material you describe. Non christians would also find it
objectionable. You cannot hope for a complete cure, but you may be
able to ameliorate the symptoms. Generally, the more persistent the
complaint, the more likely things are to change.
I personally think that it's fine to celebrate the harvest, and
educational too. But I also think that this celebration should not be
religious, and as far as I'm aware there is no requirement to make it
so. The fact that it is religious in your school might reflect the
personal views of some of the staff, which are being foisted on the
children quite inappropriately.
For more information on your rights you could look at the BHA site,
where there is a section on worship in education. Try
www.humanism.org.uk/collective.asp first, but there are other
sections which you might find relevant.
I'll pass on any other advice I receive!
Best regards,
Kim Northwood.