In 1677, shortly after Spinoza’s death, Nicolas Steno wrote an intelligence report on Spinoza’s philosophy for the Holy Office in Rome. He had come into the possession of a manuscript of Spinoza’s Ethics which he handed over to the Church’s Holy Office. This report, quoted below, is a fascinating witness to the kind of discussions on science and theology that raged in the seventeenth century. Nicolas Steno (Niels Stensen) was a brilliant pioneer in anatomy (brain and nerves), geology, palaeontology (how to explain the presence of sea fossils in high altitude deposits) and crystallography. He wrote pivotal scientific papers, then converted to Catholicism, became a priest and bishop who lived a short, pious, ascetic and generous life.

Steno had the opportunity to know Spinoza and his milieu in 1661–63.

This accusatory document was kept in a Vatican work called “Forbidden books concerning the new philosophy of Spinoza.” The text below comes from Leen Spruit and Pina Totaro, The Vatican manuscript of Spinoza’s Ethica (Leiden: Brill, 2011), 9–13. I take the liberty to quote their translation of Steno’s report in its entirety. The discovery of the manuscript of the Ethics, to whose existence I was alerted by JFH, is a very important event, and so is the book as it illuminates the evolution of Spinoza’s thought. Steno’s report follows (the impatient can jump down to the fourth paragraph for Steno’s summary of Spinoza’s philosophy):

The Holy Office has certainly been informed by other persons about the damage done by the new philosophy through a certain Spinoza in Holland; nonetheless, the seriousness of the evil and the peril of the propagation of this evil are so momentous that no effort in discovering it and in taking appropriate countermeasures can be exaggerated, in order to prevent further infections as far as possible and, if this is possible, to heal those already poisoned. This moves me to present the following report to the Holy Office.

About fifteen or sixteen years ago, when I studied at the University of Leiden in Holland, I had the occasion to become acquainted with the afore-mentioned Spinoza of Hebrew birth, but of profession without any religion, about whose doctrines I had only a confused understanding at the time. Once he had abandoned the rabbinical school of education, where he had studied for some time, he started, thanks to his acquaintance with a certain van Enden, suspected of atheism, and with the teachings of the philosophy of Descartes, to develop his own philosophy, in which he explained everything by matter only. And although in that period he paid me daily visits to see the anatomical investigations of the brain that I carried out on several animals in order to discover the place where motion begins and sensation ends, God nonetheless protected me so that he never explained to me any of his principles. In fact, God availed Himself of me to give him a chance to humble himself, first in the anatomy of the brain, showing him that neither my hand with the scalpel nor his mind with its scrutiny could arrive at establishing anything at all, but also with certain experiments concerning the heart and the muscles, where God showed me the true working of nature, thereby giving me the opportunity to overwhelm the lies proposed by those wits as true and to reprove their false presumption with the following argument: if they failed in issues as easy as these, what certainty will they be able to offer about not being deceived in difficult ones? God obviously aimed at diminishing the esteem that had arisen in me for them, so that I would not follow their errors as well as to prepare me for the grace of faith, which he was planning to grant me.

The afore-mentioned Spinoza afterwards published several books, some under his own name, others anonymously; one of these provided me with the occasion some years ago to compose a letter De vera Philosophia contra novae Philosophiae reformatorem, which I subsequently published. And although all his printed works display signs of his main intentions, he has mixed these up with views he did not share, thus avoiding the risk of being too plain, as he had been in some of the manuscripts that he composed. He possibly would have published the latter before his death, if some of his confidants had not warned him of the risk to which he exposed himself. I knew that this kind of manuscript existed, but I had never seen any of them, until some weeks ago when I happened here [in Rome] to discuss the subject of religion with a Lutheran foreigner, who after several conversations about the issue of religion brought me a manuscript without revealing its author, begging me however not to show it to others nor to inform them that he entertained similar views. And so I did at the time, not imagining the serious evil that I was to discover when reading the text, which I understood—and he confessed—to be by Spinoza. I always carry the manuscript with me, in order that nobody may by chance come into contact with the poison it contains. And so as to contribute, as much as I can, to the spreading of the glory of God, and to prevent major damage, I will here report on the main doctrines of this infidelity and on the manner in which further information may be gathered both about similar works and about the persons who adhere to them.

The basis of all their evil is a pretentious overestimation of their understanding and their desire of sensual joys.

They make of their own understanding the measure of all things, so that they may deny something simply because they cannot form a clear and distinct concept of it; in fact, they make of the human mind a part of the mind of God, and they don’t blush in saying what they know cannot be known more clearly by God than by them.

Concerning the joys of the senses they teach that true wisdom consists in enjoying the pleasures of each sense, and of theatres, smells, foods, etc., to the extent that they do not cause nuisance to themselves or damage to others; nor is there any need for thinking of penance or fear of God, or other ways to sadden the souls.

Thus, while their infelicity keeps them buried under the mud of the senses, without allowing them the time or force to raise their minds to the consideration of spiritual things, they wish, by means of mathematical demonstrations, to explain to everybody that in the universe there is only one substance, infinite and eternal, of which two attributes are known, which are equally infinite, namely infinite extension and infinite cogitation; and that all that occurs in the universe can be explained by one or the other of these attributes. They call motion a mode of extension, and thought a mode of cogitation, in such a way that to every motion corresponds an individual thought. This substance (they say) is God, of which every single body and every mind are parts. That is, if they consider God as extended, every body is part of Him; in fact, He is the collection of all bodies that have been, are, or will be in an infinite series. And as they consider him as cogitation, each thought is part of Him; in fact, he is the collection of all thought in an infinite series. They deny providence or freedom in God, but instead postulate an absolute necessity, without the intention of any end, just as in mathematics from the nature of the circle follow infinite properties without any intention of a given end, but simply as a necessary consequence. Thus, they do away with every virtue and vice, all justice of rewards and punishments, with the exception that one gives to certain persons absolute power, which everyone has with respect to the things he needs, in order to maintain everybody’s private security under public security. By consequence, there is no other sin than disobedience to the civil magistrate. It is therefore evident that all this philosophy is nothing else than the product of sense and of pride, in which vices of one’s own choice become necessity, which denies choice itself. They may well promise a reform of morals, but they go against their own principles as they propose two classes of man, one that possesses only confused knowledge and is driven by appetites, and the other that has adequate knowledge and is no slave of the appetites, but follows reason. They pretend that by providing mankind with adequate knowledge, they will transform men from slaves to free individuals, although they confess this is hard, and not for everybody—while in truth, it is for no one: For among many of those whom I have got to know, and not even in the head of these errors [sc. Spinoza], did I encounter a virtue similar to those that I found in many Catholic halfwits I met. On the contrary, less than three years ago when during my travels I paid a visit to one of them whom I had got to know many years earlier, I found him smoking a pipe surrounded by glasses of wine and beer. And presuming I shared his ideas, when he heard that I intended to prove the presence of God’s hand in the Catholic faith through the conversion of the depraved from one extreme to another, and sometimes instantaneously, as I had already happened to witness thanks to divine grace, he desired to claim that there existed no virtues more perfect than his own. And it was with great compassion that I saw a half-drunk boasting of being perfect in every virtue.

A method to gather more information would consist in this, that each time that one encounters someone interested in mathematics and Cartesian philosophy and has studied for a certain period in Holland or England, to seek his confidence and to seek information from him about the new views and about persons interested in new philosophical doctrines. Indeed, it seems morally impossible that such a person should not be informed about, or in fact already sharing in, a part or all of these errors. My reason for believing this is based upon the fact that the followers of this infidelity or apostasy place all their happiness in the enjoyment of every sense as well as in the delight of fantasy, and in order to obtain this enjoyment they seek to learn as many natural and mathematical truths as possible. For this reason, when they see persons who apply themselves to such studies, they readily approach them, both in order to learn something new and so as to see whether they can win them over, with the hope that their philosophy will reach perfection if more persons apply themselves to it. This secret of them I have discovered both thanks to the knowledge of their principles which I obtained from the examination of the afore-mentioned manuscript, and through my acquaintance with one of them, whom I wished to convert to the faith with the aid of divine grace, and who, before I discovered that he was one of them, changed his appearance several times, feigning now one creed and now another. But when he realized that someone had informed me about his views and that I opposed these merely with reasonable grounds for doubt, he eventually opened his mind entirely. [He explained that] they only rarely open their mind, because they find only very few men capable of applying themselves to it, and many, according to their view, who are too preoccupied by prejudice, who immediately detest them; to this he added his desire that I also apply myself entirely to natural philosophy, and expressed their hope that philosophy would reach a level of great perfection if more persons agreed among one another.

I fear that the evil has widely spread, and I know that the said Spinoza, while he was still alive, frequently received letters from England. Moreover, I know that a person from another country stayed several days in his house in order to better grasp it all. Finally, pondering upon remarks, when I was last in my country, made by a countryman of mine who had been in Holland, I now recognize the same principles that are also found in the manuscript. Thus, among heretics these views are widely spread, whereas I cannot remember even one Catholic who ever spoke to me about similar topics.

4 September 1677

Nicolò Stenone, the Dane, gave the Commissioner these two written pages.