The renowned Dutch philosopher Spinoza is the son of a Jewish merchant from Portugal who has fled to Holland after the Spanish occupied his country in 1580 and started implementing their laws against Jews and Muslims.
Many Portugese Jews were refugees from Spain – they had fled after the fanatically Christian rulers Isabel and Fernando prohibited all forms of Judaism and Islam in 1492. On penalty of being burnt at the stake.
Spinoza already asked questions about the different Jewish laws and proscriptions when he was very young. He also actively ignores traditions and habits considered sacred in the Jewish community. This is not appreciated at all. He is cursed and excommunicated. No one is to even be in touch with him on the same penalty of excommunication.
When he falls ill, he has to put in some effort before he can find a Jewish doctor who is actually brave enough to defy the ban. The (fictional) doctor comes from a long line of medical practitioners who have lived and worked in Amsterdam for generations. His ancestors were among the first immigrants from Spain to arrive in Holland.
'Key of Gold' is a charming tale about the fictional realtionship between the sceptic doctor and the inspired scientist-philosopher who is critically ill. He cuts lenses for a living, which takes its toll on his lungs.
What a pity the book has not been translated into Dutch.