A few years ago, Rabbi Marc D. Angel brought out a book called Maimonides, Spinoza and Us: Toward an Intellectually Vibrant Judaism . I haven’t read it, but in a review for The Forward newspaper, Steven Nadler posed the question: “What does a 12th-century rabbi in Egypt, arguably the greatest thinker in Jewish history, have in common with a 17th-century Jewish philosopher in Amsterdam who was ‘expelled from the people of Israel’ for ‘abominable heresies and monstrous deeds’ and who would go on to become the most radical philosopher of his time?” He answers that, “If the topic is the relationship between virtue and happiness, as well as how to eliminate irrational beliefs and superstitious behaviors from society, then Maimonides and Spinoza have a great deal in common. In fact, from this perspective, Spinoza carried Maimonides’s rationalist project to its ultimate logical conclusion.”
They have something else in common: both had younger brothers whose main occupation was to run the family business. Spinoza himself did actually make an effort to contribute to the enterprise, putting his shoulder to the wheel for a good six or seven years before calling it a day. Maimonides, however, had an understanding with his brother that he, Moses, would devote himself to his studies and his writing, while David would keep the show on the road.
As Sherwin Nuland, author of Maimonides (Nextbook, 2005 pp89-90), puts it:
David saw to it that the mind of his older brother was never beset by worldly cares that might divert a probing intellect from its chosen path.
As the business grew, it became necessary for David to do ever more travelling. At first this involved joining mercantile caravans that went from place to place in North Africa and then Egypt, but in time it was required that he make sea voyages of varying duration…Moses would pray for his brother’s safety at these times. He would send a letter, essentially a prayer for his safe return to the place of embarkation.”
The final letters from David to Moses and vice versa have been preserved. Cambridge University Library has the last letter that Moses received from David, in which he bemoans the tradable purchases available in the Sudanese port of Ayhdab:
“To my beloved brother R. Mos[es, son of R.] Maimon -- the memory of the righteous be blessed!
David, your brother who is longing for you – may God unite me with you under the most happy circumstances in his grace.
I am writing this letter from Aydhab. I am well, but my mind is very much troubled, so that I walk around in the bazaar and do not know – by our religion – where I [am...], nor how it is that I did not imagine how much you must worry [about m]e.
To cut a long story short: I arrived in Aydhab and found that no imports had come here [...] at all. I found nothing to buy except indigo. So I thought about what I had endured in the [des]ert [...]; then it appeared a simple matter for me to embark on a sea voyage…
My company in the Mala[bar] sea will be [...], Salim, the son of the broker and his brother's son, Makarim al-Hariri and his b[rother], and the brother of Sitt Ghazal.
Now, despite all of this, do not [worry]. He who saved me from the desert with its [...] will save me while on sea. [...]
And, please, calm the heart of the little one and her sister; do not frighten them and let them not despair, for crying to God for what has passed is a vain prayer (M. Berakhot 9:3). [...] I am doing all of this out of my continuous efforts for your material well-being, although you have never imposed on me anything of the kind. So be steadfast; God will replace your losses and bring me back to you. Anyhow, what has passed is past, and I am sure this letter will reach you at a time when I, God willing, shall have already made most of the way. But the counsel of God alone will stand (Proverbs 19:21). Our departure will probably be around the middle of Ramadan.
Moses wrote to David as he embarked for India in 1174:
"The Lord alone knows the anguish and dreariness in my heart
When parting from my beloved brother and friend.
May the Lord guard him from harm, and reunite me with him in Egypt, if the Lord so wills.”
Which apparently, he didn't. The ship sank. With the loss of the gems that David was planning to trade, the family’s financial position declined significantly. According to Nuland, “The news of his brother’s death shook Maimonides and he became quite ill following the grief.” He spent a year in deep depression, but then began to make a living and a reputation as a physician. Moses never completely recovered, however. In a letter to his friend, Japhet ben Iliahu, dayan of Acre, he wrote:
“Eight years have since passed, and I still mourn, for there is no consolation. What can console me? He grew up on my knees; he was my brother, my pupil. He was engaged in business and earned money that I might stay at home and continue my studies. He was learned in the Talmud and in the Bible and an accomplished grammarian. My one joy was to see him.”
The nature of the relationship between Baruch and his brother Gabriel is unfortunately not recorded. However, it seems that Baruch took his filial duties seriously joining his father’s fruit importing business in 1649. According to Nadler in his own book Spinoza’s Ethics: An Introduction (Cambridge University Press):
Spinoza may have excelled in school, but, contrary to the story long told, he did not study to be a rabbi. In fact, he never made it into the upper levels of the educational program, which involved advanced work in Talmud. In 1649, his older brother Isaac, who had been helping his father run the family business, died and Spinoza had to cease his formal studies to take his place. When Michael died in 1654, Spinoza found himself, along with his other brother Gabriel, a full-time merchant, running the firm “Bento y Gabriel de Spinoza.” He seems not to have been a very shrewd businessman, however, and the company, burdened by the debts left behind by his father, floundered under his direction.
Spinoza did not have much of a taste for the life of commerce anyway. Financial success, which led to status and respect within the Portuguese-Jewish community, held very little attraction for him. By the time he and Gabriel took over the family business, he was already distracted from these worldly matters and was devoting more and more of his energies to intellectual interests.
In 1656, Spinoza was ready for a career change and managed to extricate himself from the business and its debts. In any case, that same year, he was subject to the famous herem (commonly regarded as an excommunication, though issued by the lay leadership of the community – the Ma’Amad – rather than its rabbinical authorities), which would have made a continued role in the business untenable, even if he’d wanted to continue to play a role. It seems that Gabriel soldiered on in the business. In 1664, he left for Barbados. In 1671, he moved to Jamaica, became a naturalised British subject and spent his last years there