Jewish academic and Hebrew scholar Irene Lancaster shares her thoughts on a new book on reason that aims to bring Christians and Jews together. 

As the Jewish community commences the festival of Chanukah on Sunday night, the 8-day festival of the miracle of the lights (and don't forget to listen to the Classic FM Chanukah musical celebration programme on Boxing Day, 9.00 pm), it might seem apt to celebrate a new book which aims to bring Christians and Jews closer together.

During the last two thousand years, Jewish experience of relations with Christians has been negative, to say the least, and has usually ended in tears (by which I mean humiliating degradations, forcible conversions, expulsions from places of residence, and sometimes even mass slaughter - these issues have been discussed here).

However, in a gesture signalling that things may be looking up, on Friday King Charles visited a Jewish community centre in North London and participated with gusto in pre-Chanukah celebrations. We saw the monarch dancing the hora to the music of Fiddler on the Roof with Jews of all ages, including Holocaust survivors.

And award-winning Jewish film director, Steven Spielberg, who has his own story of dealing with venomous antisemitic abuse in the US, is this week's guest on BBC Radio Four's Desert Island Discs.

The lesson of Chanukah must therefore be that whatever is thrown at you, things can only get better, and now many non-Jewish people are also beginning to appreciate that Jewish message.

So, this seems like a good time to say a few words about an excellent book that has just been published by Brill, Understanding the Evolving Meaning of Reason in David Novak's Natural Law Theory, by Dr Jonathan Milevsky of Toronto.

Rabbi Professor David Novak is regarded as one of the leading North American thinkers who writes on the status of non-Jewish people in the larger scheme of things, and specifically in covenantal relation with the Jewish people, and this book discusses the development of Novak's thought with respect to the relationship between Jews and Christians.

Professor Novak closely follows the great Catholic mediaeval thinker, Thomas Aquinas (1225-74), when outlining his ideas on 'reason' and 'natural law'.

So I asked former Archbishop of Canterbury, Dr Rowan Williams to explain to me what Aquinas thought about these issues. This is what Dr Williams told me, based mainly on Aquinas' Summa Theologiae,  questions 90, 91, 94, 97 and 99:

Natural Law is 'a way of thinking embedded in human nature that directs human beings towards appropriately performing the actions that are distinctive [propriae] to human beings.'

It is 'contained primarily in the eternal law [of God], and secondarily in the natural judgement of human reason.'

'All kinds of law are oriented to friendship [amicitia], either of one human being to another or between human beings and God.'

'The written law corrects natural law by supplementing it...it [natural law] having been corrupted in human hearts.'

'There are five ways of talking about law - eternal law, natural law, divine law, human law, and the kindling of sin [this last refers - I think - to Paul's argument that one effect of law can be to make us more conscious of the possibilities of sin].

'Divine law is a sharing in eternal law which orients us to our supernatural goal [i.e. to holiness and relation with God], just as natural law is what orients us to our natural goal [i.e. harmonious relations between human beings, or the common good].'

'Law is a kind of ordering of the reasoning mind towards a common good...No precept can have the force of law unless it looks towards the common good.'

And last: 'Natural law can be changed by divine or human law adding to it or taking away possible implications from it - but only very seldom, and with a particular aim in mind, not as regards its basic principles.''

Therefore, if a summary of these ideas is possible, it appears that 'natural law' or 'reason' is 'embedded' within us, and guides us towards doing the right thing. It seems therefore that G-d's Law and our own ability to think things through can come together as one, thus allowing a person, whether Jewish or not, to behave in a way that is deemed good.

As an aside, it is interesting to note that Thomas Aquinas writes about his indebtedness to the thought of the great Jewish medieval thinker, Moses Maimonides (known as the Rambam) who lived from 1135-1204. But Maimonides himself was heavily influenced by the work of his Spanish predecessor, Abraham ibn Ezra (1089-1164), who famously stated in his Introduction to the Commentary on the Torah, Path Three (on the Christian approach to the biblical text) that 'the angel between a person and his or her G-d is their intelligence.'

This casts a new light for some on the meaning of the term 'angel' and the place of our own reasoning powers in the scheme of things. G-d mediates with human beings through implanting intelligence within, as our guardian angel.

Sometimes a really profound book is worth purchasing, and for those who are serious about meaningful dialogue and want to go beyond the surface of things, Jonathan Milevsky's book on the place of reason, the intellect and 'natural law' in Jewish Christian relations is indispensable.

So whether you celebrate Chanukah or Christmas, I would like to wish you all the very best for the festivities, as I now prepare to light the Chanukah lights and organize the musical treats for the Shul Chanukah Party.

I would like to leave you with the memory of a very special occasion in which to rejoice.