This post fits neatly into the 'tsores from mishpocheh' sub-section of this series.
In her (highly recommended) recent book, Betraying Spinoza, Rebecca Goldstein hints at the possibility that theological differences may not have been entirely responsible for Spinoza's excommuncation from the Amsterdam 'Portuguese' Jewish community. She writes (p251):
His sister Miriam had had one child before she died, Daniel. The child had been less than a year old when the mother had died. Miriam, his litle mother, his mais velha. He can still remember her kindness to him, though she was only a child herself, eight years old, motherless and no doubt forlorn herself. Her husband, Samuel de Casseres, had married Spinoza's other sister, Rebecca, and, in addition to Daniel, they had had more children together......
There had been a certain unpleasantness with Rebecca, involving money. He hadn't thought of it in years. It was the sort of thing that can happen in families, that happens quite often. It had involved the distribution of their father's assets. Rebecca was already promised to Casseres, with his many ties to the synagogue authorities, and Spinoza could easily deduce how the parnassim would be inclined to decide in favour of Casseres's future wife. So Spinoza had done the unthinkable. He had brought the case before the state authorities, and they had decided in his favor.
Perhaps this act, more than any of his blasphemous views – whether of God, the Jews, or immortality – had incited the parnassim to fulminate against him with such bombastic excess in the writ of excommunication that they had prepared, and which he had never deigned to recognise.
Polish poet, Zbigniew Herbert, describes the dispute thus:
In the eyes of his biographers Spinoza was unmistakably an ideal wise man: exclusively concentrated on the precise architecture of his works, perfectly indifferent to material affairs, and liberated from all passions. But an episode in his life is passed over in silence by some biographers, while others consider it only an incomprehensible, youthful whim.
Spinoza's father died in 1656. In his family Baruch had the reputation of an eccentric young man who had no practical sense and wasted precious time studying incomprehensible books. Due to clever intrigues (his stepsister Rebecca and her husband Casseres played the main role in this) he was deprived of his inheritance. She hoped the absentminded young man would not even notice. But it happened otherwise.
Baruch initiated a lawsuit in court with an energy no one suspected him to have. He hired lawyers, called witnesses, was both matter-of-fact and passionate, extremely well-oriented in the most subtle details of procedure and convincing as a son injured and stripped of his rights.
They settled the division of the estate relatively quickly (clear legal rules existed in this matter). But then a second act of the trial unexpectedly followed, causing a general sense of unpleasantness and embarrassment.
As if the devil of possessiveness had entered him, Baruch began to litigate over almost each object from his father's house. It started with the bed in which his mother, Deborah, had died (he did not forget about its dark green curtains). Then he requested objects without any value, explaining he had an emotional attachment to them. The judges were monumentally bored, and could not understand where this irresistible desire in the ascetic young man came from. Why did he wish to inherit a poker, a pewter pot with a broken handle, an ordinary kitchen stool, a china figure representing a shepherd without a head, a broken clock which stood in the vestibule and was a home for mice, or a painting that hung over the fireplace and was so completely blackened it looked like a self-portrait of tar?
Baruch won the trial. He could now sit with pride on his pyramid of spoils, casting spiteful glances at those who tried to disinherit him. But he did not do this. He only chose his mother's bed (with the dark green curtain), giving the rest away to his adversaries defeated at the trial.
No one understood why he acted this way. It seemed an obvious extravagance, but in fact had a deeper meaning. It was as if Baruch wanted to say that virtue is not at all an asylum for the weak. The act of renunciation is an act of courage-it requires the sacrifice of things universally desired (not without regret and hesitation) for matters that are great, and incomprehensible.
As for the Leibniz sibs, I know precious little, other than the fact his sister Anna Catharina's son, Friedrich Simon Löffler, was his sole heir. I'm sure some sort of broigus – acknowledged or not – lies behind that decision.