Was Descartes murdered?

René Descartes is a French philosoper, mathematician and scientist born in March 1596 and dead in February 1650. He is one of the most notable intellectual figure of his time. HIs contribution to mathematics include the Cartesian coordinate system, the analytical geometry, and the discovery of infinitesimal calculus and analysis. His contribution to philisophy is summarised in his aphorism "I think, therefore I am". In his "Discours de la méthode", he lays four rules of thought to ensure that our knowledge is evidence-based:

"The first was never to accept anything for true which I did not clearly know to be such; that is to say, carefully to avoid precipitancy and prejudice, and to comprise nothing more in my judgment than what was presented to my mind so clearly and distinctly as to exclude all ground of doubt."

The tirty years' war spans over the period 1618 to 1648. Over the period, it will involve all countries in Europe except England and Russia. It remains one of the longest wars in Europe and one of the most brutal one with over 8 million deaths. It started as a religious war within the Roman Holy Empire at the time of the spread of the Reform but ended as a major geopolitical shift in Europe, marking the end of feodality and the emergence of nation-states, at the origin of modern Europe

In the Baltic, the Thirty years' war signed the end of Denmark as a regional power and the emergence of Sweden as the regional power. The Swedish king Gustav II-Adolph and his armies were determinant in the victory of the protestants against the Emperor Ferdinand II and the catholic leagues. However, he dies in 1632 at the battle of Lützen.

Interestingly, while being catholics, the French king Louis XIII took side with the protestant to limit the power of Ferdinand II. In 1648, a series of treaties ended the war with the Westphalia peace and set the boundaries of new states that will shape the future of Europe.

Queen Christina is the daughter of King Gustav II-Adolph. In 1644, reaching majority, she becomes "King" of Sweden. After negotiating the peace of Westphalia, she is crowned queen of Sweden, the new regional power in the Baltic. She ensure rapidly peace with Danemark and engage in a Swedish "renaissance", inviting artists, painters and philosophers in the court of Sweden, establishing a library. She wanted Stockholm to become the Athen of the north. After ten years, the state gets bankrupted and Christina ends-up abdicating.

It is in this context that Descartes departs to Sweden on 1st September 1649 and arrives in Stockholm in the winter, responding to the invitation of Queen Christina.

While in Stockholm, Descartes lives in Gamla Stan, few hundred metres from the Queen castle, hosted in the French Embassy. Every morning, the Queen was asking him to join her in the Castle to converse. In the aftermath of the Thirty years' war, François Viogué, an apostolic missionary was sent to the court of Queen Christina and hosted in the French Embassy with Descartes. His mission was to get Sweden back to the catholic faith.

One of the pilar of the catholic faith at the time resided in the concept of transubstantation, the change of substance or essence by which the bread and wine offered in the sacrifice of the sacrament of the Eucharist during the Mass, become, in reality, the body and blood of Jesus Christ. Challenging the principle of transubstantation was at the centre of the reform.

Descartes, based on his principles of physiology was considering the transubstantation as a belief not to be supported by any evidence, and therefore not to be considered.

At the beginning of February, Descartes feels suddenly sick and dies two weeks later. Persitent rumours start to emerge about the possible poisoning of Descartes, in fear that his ideas against transubstantation would prevent Queen Christina to revert to Catholicism. As of today, still two theories are considered regarding the death of Descartes:

• Descartes was poisonned by François Viogué, in fear that his contact with Queen Christina would influence her against the principle of transubstantation and therefore converting back to catholicism. To support this hypothesis, historian are reporting the fact that Viogué gave a Holy Host to Descartes the morning he got sick, that the symptoms experienced by Descartes were characteristic of arsenic poisoning and that Descartes asked for an emetic treatment that could only be justified if one would suspect poisonning.
• Descartes host was returning to Sweden with a severe pulmonary infection. Descartes became ill a few days after the return of his host, with similar symptoms, suggesting that he could have been infected by a virus/bacteria brought back by his host.