Rica to Nathanial Lévi, a Jewish physician in Livorno
You ask me what I think of the virtue of amulets and the potency of talismans. Why do you ask me ? You are a Jew, and I am a Muhammadan, which is to say that we are both quite credulous.
I always carry on me more than two thousand passages of the holy Qur’an ; I attach a little packet to my arms in which are written the names of more than two hundred derviches ; those of Ali, Fatmé, and all the pure are hidden in more than twenty places in my clothing. 
Yet I do not disapprove of those who reject the virtue we attribute to certain words ; it is much more difficult for us to answer their arguments than for them to answer our experiences.
I wear all these holy scraps from long habit, to conform to a universal practice ; I think that if they have no more virtue than the rings and other ornaments we put on, they have no less. But you, you place all your confidence in some mysterious letters, and without that protection you would be in continual anxiety. 
Men are truly unfortunate : they float endlessly between false expectations and ridiculous fears, and instead of depending on reason, they think up monsters to intimidate them or phantoms that seduce them.
What effect do you expect the arrangement of certain letters to have ? What effect do you expect their disarrangement to be able to trouble ? What relation have they with the winds, to calm tempests ; with gunpowder, to defeat its energy ; with what the physicians call humeur peccante,  and the morbific cause of illnesses, to cure them ?
What is extraordinary is that those who tax their reason to make it connect certain events to occult virtues, have no less an effort to make to keep themselves from seeing the true cause.
You will tell me that certain spells have caused battles to be won ; and I will tell you that you must blind yourself not to find in the situation of the terrain, the number or courage of the soldiers, and the experience of the captains, sufficient causes to produce that effect, the cause of which you want not to know.
I will allow with you for the moment that there are spells ; supposed with me in turn for a moment that there are none, for that is not impossible. This concession you make to me does not prevent two armies from being able to fight : would you have it that, in that case, neither of the two can achieve the victory ?
Do you believe their destiny will remain undecided until some invisible power comes to determine it : that all blows will be lost, all the prudence vain, and all the courage useless ?
Do you think that death, made present in such occasions in a thousand ways, cannot produce in the minds those frightened panics which you have such difficulty explaining ? Do you expect that in an army of a hundred thousand men there cannot be a single timid man ? Do you believe that that man’s discouragement cannot produce the discouragement of another ; that the second who is leaving a third does not soon cause him to abandon a fourth ? It takes no more than that for despair of winning suddenly to seize an entire army, and seize it all the more easily the more numerous it is.
Everyone knows and everyone feels that men, like all creatures that tend to preserving their being, passionately love life. We know that in general, and we ask why in a particular situation they have feared losing it ?
Although the holy books of all nations are filled with these panic or supernatural terrors, I am imagining nothing so frivolous, because in order to make sure that an effect that can be produced by a hundred thousand natural causes is supernatural, one must first have examined whether none of those causes has acted, which is impossible.
I shall not say more about it, Nathanial ; it seems to me that the matter does not merit such serious discussion.
Paris this 20th day of the moon of Chahban 1720
P. S. As I was closing, I heard someone in the street hawking a letter from a provincial physician to a physician in Paris (for here all trifles are printed, published, and purchased) ; I thought I should send it to you, because it has some connection with our subject. There are many things that I do not understand, but you who are a physician must understand the language of your colleagues.
Letter from a provincial physician to a physician in Paris
There was in our city a sick man who had not slept for thirty-five days. His physician prescribed him opium, but he could not resign himself to taking it, and when he had the cup in his hand he was more uncertain than ever. Finally he said to his physician : Monsieur, leave me in peace just until tomorrow ; I know a man who does not practice medicine, but who has in his house a limitless number of remedies for insomnia : allow me to send for him, and if I do not sleep tonight, I promise you I will come back to you. The physician dismissed, the patient had the bed curtains closed, and said to a little servant : Listen, go to the house of M. Anis, and tell him to come talk with me. M. Anis arrives : My dear M. Anis, I am on my deathbed ; I cannot sleep : might you not have in your shop La C. du G.  or some devotional book composed by an R. P. J.  that you have been unable to sell ?  For often the most kept remedies are the best. Monsieur, said the bookseller, I have Father Caussin’s La Cour sainte in six volumes  to serve you ; I shall send it to you ; I hope it helps. If you want the works of Reverend Father Rodriguez, a Spanish Jesuit,  be sure to get it ; but take my advice, and let us stick with Father Caussin ; I hope that with God’s help one period of Father Caussin’s will do as much for you as an entire sheet of La C. du G. Thereupon M. Anis left and rushed to get the remedy in his shop. La Cour sainte arrived ; they shake the dust from it ; the patient’s son, a young schoolboy, begins to read it. He felt its first effect ; at the second page he was pronouncing in an ill-articulated voice, and already the whole company was feeling a weakness coming on ; an instant later everyone was snoring but the patient, who after a long distress, finally dozed off.
The physician arrived early in the morning : Well, did we take my opium ? No one answered ; the wife, the daughter, and the little boy, in the throes of joy, showed him the Father Caussin. He asks what that is ; they say to him : Long live Father Caussin ; we must have him bound. Who would have thought it ? Who would have believed it ? It is a miracle. Here, monsieur, have a look at Father Caussin, this is the volume that put my father to sleep ; and thereupon they explained to him how that had come about.
The physician was a subtle man, full of the secrets of the cabala and the power of words and spirits. That struck him, and after several reflections he decided utterly to change his practice. There is a most singular fact, he said. I have an experiment in hand ; it must be pursued further. Now why could a spirit not transmit to its work the same qualities it has itself ? Do we not see this every day ? At least that is worth being tried ; I am tired of apothecaries, their syrups, their juleps,  and all the Galenic drugs  ruin patients and their health : let us change our method, let us test the virtue of spirits. On this thought he set up a new pharmacy, as you shall see by the description I am going to give you of the principal remedies he put into practice.
A purgative infusion
Take three folios of Aristotle’s Logic in Greek, two folios of the most incisive treatise of scholastic theology, as for example the subtle Scot,  four of Paracelsus, one of Avicenna, six of Averrhoes, three of Porphyry, as many of Plotinus, as many of Iamblicus  : infuse them all together for twenty-four hours, and take four pinches per day.
A more violent purgative
Take ten A** du C*** concerning the B** and the C** des I**,  distill them in a double boiler ; dilute a drop of the pungent, piquant humour they will yield into glass of ordinary water ; confidently swallow the whole.
Take six orations, any twelve funeral orations, taking care however not to use those of M. de N.,  a collection of new operas, fifty novels, thirty new memoirs ; put all into a crock, let it digest for two days, then distill it with a feu de sable  ; and if all that is not sufficient :
Another, stronger one
A very simple remedy to cure asthma
Read all the works of the Reverend Father Maimbourg, former Jesuit,  taking care not to stop before the end of each sentence, and you will gradually the faculty of breathing returning to you, with no need to repeat the remedy.
To protect against scabies, rash, ringworm, and horse farcy 
Take three categories  of Aristotle, two metaphysical degrees,  a distinction,  six verses of Chapelain,  one phrase taken from the letters of the abbé de Saint Cyran  ; write it all on a piece of paper which you will fold, attach to a ribbon, and wear around the neck.
Miraculum Chymicum de violenta fermentatione cum fumo, igne, et flammā
Misce Quesnellianam infusionem , cum infusione lallemaniana  ; fiat fermentatio cum magnā vi, impetu, et tonitru, acidis pugnantibus, et invicem penetrantibus alcalinos sales : fiet evaporatio ardentium spirituum ; pone liquorem fermentatum in Alembico ; nihil inde extrahes, et nihil invenies, nisi caput mortuum .
Recipe Molinae  anodini chartas duas, Escobaris relaxativi paginas sex , Vasquii emollientis folium unum  ; infunde in aquæ communis lib. iiii ad consumptionem dimidiæ partis colentur et exprimantur ; et in expressione dissolve Bauni detersivi , et Tamburini abluentis folia iii. 
Fiat clister .
In clorosim, quam vulgus pallidos colores,  aut febrim amatoriam appelat
These are the drugs which our physician put into practice, with the success one can imagine. He did not wish, he would say, in order not to ruin his patients, make use of rare remedies, which are almost nonexistent, as for example a dedicatory epistle that has made not a single person yawn, too short a preface, a pastoral letter written by a bishop, and the work of a Jansenist scorned by a Jansenist or admired by a Jesuit. He said that these sorts of remedies are only good for supporting charlatanry, against which he had an invincible aversion.
[Supplementary Letters VII and VIII of the 1758 edition would be placed here.] |Supplementary Letter VII|