Bava Metzia 30b ~ Visiting the Sick

 בבא מציעא ל ,ב 

דתני רב יוסף והודעת להם זה בית חייהם את הדרך זו גמילות חסדים (אשר) ילכו זה ביקור חולים בה זו קבורה ואת המעשה זה הדין אשר יעשון זו לפנים משורת הדין

Rav Yosef taught: The verse states (Ex. 18:20):

"You shall make known to them" -this refers to their livelihood

"The way" - this refers to good deeds

"That they may walk"  - this refers to visiting the sick...

According to Rav Yosef, Moses was instructed to let the people know that they must pursue a livelihood, perform kind acts and visit the sick.  Let's remind ourselves of the importance of that last one, with a repost from Nedarim 39. There, we read the following:

נדרים לט, ב - מ, א

תניא ביקור חולים אין לה שיעור ... אמר אביי: אפי' גדול אצל קטן רבא אמר אפי' מאה פעמים ביום אמר רבי אחא בר חנינא כל המבקר חולה נוטל אחד מששים בצערו

יצא ר' עקיבא ודרש: כל מי שאין מבקר חולים כאילו שופך דמים. כי אתא רב דימי אמר: כל המבקר את החולה גורם לו שיחיה וכל שאינו מבקר את החולה גורם לו שימות

Visiting the sick is a mitzvah that has no limit... Abaye said that even an important person must visit a lesser person who is ill...Rava said: [you must visit a sick person] even one hundred times a day...Rabbi Acha bar China said: "Whoever visits a sick person takes away one-sixtieth of his suffering...

Rabbi Akiva expounded and said: "Whoever does not visit the sick, it is as if he sheds blood." When Rav Dimi came [from Israel to Babylon] he said: "Whoever visits the sick causes the person to live, and whoever does not visit the sick, causes the person to die." (Nedarim 39b-40a)

Some time ago I visited the famous Grady Memorial Hospital in Atlanta, and was privileged to be given a tour of their new Neurocritical Care Unit, part of the Marcus Stroke and Neuroscience Center (and thank you, Bernie "Home Depot" Marcus).   While the unit has all the fancy equipment you'd expect, what impressed me the most was a feature I had not seen in any other intensive care unit (ICU): every patient room has an adjoining suite where a family member can eat, sleep, shower and wait (and there is a lot of waiting in ICUs). There are no visiting hours; the family member literally lives in the ICU with their loved one.  My tour guide explained that the unit sees the presence of  visitors as a way of offering the best care to the patient. It is a wonderful approach to the care of the sick - but it wasn't always like that.

A HISTORY OF VISITING THE SICK - IN HOSPITALS

Visiting times in hospitals still vary greatly, and many have an open door policy. But not too long ago, you might only be able to visit a patient in a hospital for a couple of hours each week. In the 1870s, Doncaster Royal Infirmary in Britain limited visiting to three afternoons a week - which was a more generous policy than that of the Royal Berkshire Hospital, which allowed only one 15 minute visits twice a week. In a survey of over 400 British hospitals conducted in 1988, over a quarter of those which replied allowed visiting for no more than two hours a day. Perhaps these restrictive policies were in response to some visitors who abused the generosity of Britain's glorious National Health Service. 

““[A more open visiting policy] proved to be a disaster, primarily because of abuse of the system by visitors. Many would arrive promptly at 8 am and stay all day. They would bring sandwiches and flasks . . . and camp out by their relative’s bed . . . Others would eat patients’ food, [and] ask for extra cups of tea...there was even a threat of violence from a visitor asked to leave temporarily...”

— Alderman B. Hospital visiting hours. BMJ 1988;296:1798-9.

HELP PATIENTS GET WELL SOONER - BY VISITING THEM

In 2006 an Italian group reported the results of a study on the effects of hospital visitors on patient outcomes in its small intensive care unit.  The ICU changed its visiting policy from a restricted one (one visitor twice a day for thirty minutes) to an unrestricted one every two months.  After two years of this alternating policy, the authors compared the outcomes of their 226 patients. Despite significantly higher environmental microbial contamination during the unrestricted visiting periods, septic complications were similar. But the risk of cardiocirculatory complications was twice as high in the restricted visiting periods, which were also associated with a (non-significantly) higher mortality rate. The unrestricted group was associated with a greater reduction in anxiety score and a significantly lower increase in thyroid stimulating hormone from admission to discharge. The authors concluded that "liberalizing the visiting hours seems to be more protective because it is associated with a reduction in severe cardiovascular complications."

Incidence, with Odds Ratio and 95% Confidence Intervals, of septic and major cardiovascular complications in patients enrolled during the restricted (RVP) and unrestricted visiting periods (UVP) adjusted for age, gender, and time of enrollment. RR indicates relative risk; UT, urinary tract; pul., pulmonary; and CV compl., cardiovascular complication. From Fumagalli et al. Reduced Cardiocirculatory Complications With Unrestrictive Visiting Policy in an Intensive Care Unit Results From a Pilot, Randomized Trial. Circulation. 2006;113:946-952.

Writing in The Journal of the American Medical Association in 2004, Donald Berwick and Meeta Kotogal called for a change in the policy of restricted visiting hours in intensive care units.  They noted three areas which are often of concern to ICU staff when considering the question of visiting hours.  They also noted that although these concerns seem reasonable, the scientific literature tells "quite a different story."

Physiologic Stress for the Patient: "The concern that the patient should be left alone to rest incorrectly assumes that family presence at the bedside causes stress. The empirical literature suggests that the presence of family and friends tends to reassure and soothe the patient, providing sensory organization in an overstimulated environment and familiarity in unfamiliar surroundings. Visits of family and friends do not usually increase patients’ stress levels, as measured by blood pressure, heart rate, and intracranial pressure, but may in fact lower them. Nursing visits, on the other hand, often increase stress." 

Barriers to the Provision of Care: "The second concern is that the unrestricted presence of loved ones at the bedside will make it more difficult for nurses and physicians to do their jobs and may interfere with the delivery of care. The evidence suggests, however, that the family more often serves as a helpful support structure, increasing opportunities for patient and family education, and facilitating communication between the patient and clinicians." 

Exhaustion of Family and Friends: "The third concern is that constant visiting with the patient may prove exhausting for family and friends who fail to recognize the need to pace themselves. While that does sometimes happen, it is also true that open visiting hours help alleviate the anxiety of family and friends, allowing them to spend time with the patient when they want and to feel more secure and relaxed during the time they are not with the patient. One study found that open visitation had a beneficial effect on 88% of families and decreased anxiety in 65% of families."

A review of visitation policies in ICUs produced by the American College of Critical Care Medicine Task Force went one step further and found "no evidence that pets that are clean and properly immunized should be restricted from the ICU environment." So don't forget to bring the dog next time you visit a family member or friend in the ICU (or anywhere else for that matter). 

“...the preponderance of the literature supports greater flexibility in ICU visitation policies. Descriptive studies of the physiologic effects of visiting on mental status, intracranial pressure, heart rate, and ectopy demonstrated no physiologic rationale for restricting visiting. In fact, in seven of 24 patients with neurologic injuries, family visits produced a significant positive effect, measured by decrease in intracranial pressure.”

— Davidson et al. Clinical practice guidelines for support of the family in the patient-centered intensive care unit: American College of Critical Care Medicine Task Force 2004–2005. Critical Care Medicine 2007; 35 (2): 612.

HOW TO VISIT A FRIEND WHO'S SICK - THEN, AND NOW

Most of the evidence about the benefits of visiting the sick that we've been discussing have centered on the ICU- because that's where most of the research has been done. But for most of the time, an ill friend will not be in the ICU, or even in the hospital. Instead they will be at home, and so that is where the visit will occur.  Sadly, the ability to be a friend to a friend who is sick does not come easy to all of us.  Here's what Letty Pogrebin noted, in her recent book How to be a Friend to a Friend Who's Sick:

It's not uncommon for people to freeze or panic in the company of misery, botch gestures that were meant to ease, attempt to problem-solve when we have no idea what we're talking about, say the wrong thing, talk too much, fidget in the sick room, sit too close to the patient or stand too far away. Some of us don't visit our sick friends at all...

The Talmud sensed that visitors need some guidelines as to how to behave, and so in the daf that we will learn tomorrow, Rav Shisha suggested the following rule: "One should not visit a sick person in the first three hours of the day or in the last three hours of the day." In addition, the Talmud notes that "one who goes to visit the sick should not sit on the bed nor on a bench or a chair, but instead should wrap himself up in his cloak and sit on the ground, because the divine presence rests above the bed of a sick person." While we may no-longer follow this advice, the suggestion that we take our visits to the sick seriously is one that we should heed. Let's close with some more advice, updated for the modern era, from Pogrebin's 2013 handbook (p86-86):

1. Ask the patient to be honest with you and all their friends.

2. Be honest with yourself about your attitude toward the visit.

3. Think through your role in the visit.

4. Don't visit if you can't abide silence.

5. Be prepared to respond without flinching to whatever scene or circumstances greet you during your visit.

6. Be sensitive to your friend's losses.

7. Talk honestly with your children about the demands illness makes on friendship and how important it is to visit people who want company.

“What is the reward given for visiting the sick in this world? “God will guard him and restore him to life and he will be fortunate on earth, and You will not give him over to the desire of his foes.” [Ps 41:3.]:
”God will guard him” - from the evil inclination.
”And restore him to life” - from his suffering.
”And he will be fortunate on earth”- in that everyone will take pride in him.
”And You will not give him over to the desire of his foes”- for he will have good friends... ”

— Nedarim 40b

[Repost from Nedarim 39 and Sotah 14.]

Bava Metzia 24a ~ Torture

בבא מציא כד, א

מר זוטרא חסידא אגניב ליה כסא דכספא מאושפיזא חזיא לההוא בר בי רב דמשי ידיה ונגיב בגלימא דחבריה אמר היינו האי דלא איכפת ליה אממונא דחבריה כפתיה ואודי

Mar Zutra the Pious was involved in an incident in which a silver cup was stolen from his host. Later, Mar Zutra saw a certain student wash his hands and dry them on his friend's garment. Mar Zutra said: "this is the one who stole the cup, for he has no consideration for his friend's property. Mar Zutra bound the student to a post and coerced him, and he confessed to the crime (Bava Metzia 24a).

This is an incredible passage. When I first encountered it I wasn't certain I had understood it correctly. But there it was, in black and white. The Pious Mar Zutra had, in essence, tortured a confession out of a student.

Courtesy of Wikimedia.

The phrase that describes this is כפתיה ואודי "they bound him and he confessed." The root of the word to bind is כפת, which is used in rabbinic literature to mean to tie or to bind. Rabbi Asher ben Yechiel (Germany ~1250-1327), known as the Rosh, is certain that the suspect was tortured. In his commentary on this passage he wrote וכפתיה בשוטי עד דאודי "he flogged him with rods until he confessed." (As in חושך שבטו שונא בנו ואהבו שחרו מוסר "spare the rod and spoil the child," from Proverbs 13:24.) Rabbi Betzalel ben Avraham Ashkenazi (Israel ~1520-1594) in his commentary called Shitah Mekubetzet agrees that coercion was used, although he is unsure if it was physical or psychological:

כפתוהו ואודי. יש מפרשים כפתוהו על העמוד והלקוהו בשוטים. ויש מפרשים כפתיה בדברים שנדוהו אם לא יודה האמת

Some explain that he was tied to post and flogged. Others explain that he was verbally coerced (and threatened with excommunication) until he confessed.

False Confessions

In a 2010 paper published in the Stanford Law Review, Brandon Garett notes that DNA testing has now exonerated over forty people who falsely confessed to rapes and murders. He wonders how an innocent person could convincingly confess to a crime he never committed. For example, in 1990  Jeffrey Deskovic a seventeen-year-old, was convicted of rape and murder. Deskovic was a classmate of the fifteen-year-old victim, had attended her wake, and was eager to help solve the crime. During one of several police interrogations he “supposedly drew an accurate diagram,” which depicted details concerning “three discrete crime scenes” which were not ever made public. "In his last statement, which ended with him in a fetal position and crying uncontrollably," wrote Garrett, "he reportedly told police that he had “hit her in the back of the head with a Gatoraid [sic] bottle that was lying on the path.” Police testified that, after hearing this, the next day they conducted a careful search and found a Gatorade bottle cap at the crime scene."

“Scholars increasingly study the psychological techniques that can cause people to falsely confess and have documented how such techniques were used in instances of known false confessions.”

— Garrett, B.L. The Substance of False Confessions. Stanford Law Review 2010. 62 (4): 1051-1119.

Deskovic was convicted of rape and murder and served more than fifteen years of a sentence of fifteen years to life. Then in 2006, new DNA testing not only excluded him, but also matched the profile of a murder convict who subsequently confessed and pleaded guilty. So how did Deskovic know all the details of the crime to which he confessed? Here is what the District Attorney noted in the post-exoneration inquiry:

...Given Deskovic’s innocence, two scenarios are possible: either the police (deliberately or inadvertently) communicated this information directly to Deskovic or their questioning at the high school and elsewhere caused this supposedly secret information to be widely known throughout the community.

Another paper, this time in the North Carolina Law Review, analyzed 125 cases of "proved interrogation-induced false confessions, which, the authors note with some pride, is "the largest cohort of interrogation-induces false confession cases ever identified and studied in the literature." It makes terrifying reading.  

It is of course really hard to study in the laboratory the psychological effects of torture and coercion and how they produce false confessions.  But scientists try anyway. For example, a very recent paper from a team from the New School for Sociological Research in New York and the University of California studied the effect of sleep deprivation on false confessions.  When compared to those who had rested, participants were over four times more likely to sign a false statement if they were deprived of one night's sleep.  In another recent peer-reviewed paper, (Constructing Rich False Memories of Committing Crime) psychologists used suggestive retrieval techniques on some rather nice Canadian undergraduates. They found that up to 70% of those interviewed 

were classified as having false memories of committing a crime (theft, assault, or assault with a weapon) that led to police contact in early adolescence and volunteered a detailed false account. These reported false memories of crime were similar to false memories of noncriminal events and to true memory accounts, having the same kinds of complex descriptive and multisensory components.

They continue: 

Our finding that young adults generated rich false memories of committing criminal acts during adolescence supports the notion that false confessions and gross confabulations can take place within interview settings. The Innocence Project has shown that about 25% of false convictions are attributable to faulty confession evidence...The kind of research presented here is essential in the quest to help prevent memory-related miscarriages of justice.

Back to Mar Zutra the Pious

We know little about Mar Zutra, but for those studying the one-page-a-day Daf Yomi cycle, the last place we learned his teachings was in Bava Kamma. On Shabbat, when using a stone from a wall to wipe himself after using the bathroom, Mar Zutra the Pious would then return the stone to its place in the wall. He would later instruct his servant to cement the stone back into place, so as not to damage the wall.  He was, then, a man who acted to preserve the property rights of others, even in the most intimate of circumstances, when he knew no one would be watching.  And there's another story about Mar Zutra's piety - this one with more bearing on today's teaching in the Talmud. In the tractate Nedarim, we are taught the following:  

דמר זוטרא חסידא כי מחייב בר בי רב שמתא משמית נפשיה ברישא והדר משמת בר בי רב וכי עייל לביתיה שרי לנפשיה והדר שרי ליה ואמר רב גידל

When Mar Zutra the Pious placed excommunicated a student, Mar Zutra first excommunicated himself, and only then the student.  On arriving home, he lifted the ban from himself and then from the disciple.

Tosafot offers two explanations for this rather unusual behavior. First, he excommunicated himself so as not to forget that he had done so to a student. This would force him to recall his student, and when the time came, he would lift the ban. The second proposal offered by Tosafot is that Mar Zutra acted in this way as a sort of penitence: excommunicating another person was an extreme measure, and Mar Zutra reminded himself of this by imposing the same punishment on himself.

תוספות נדרים דף ז, ב 

פר"ת שזה היה עושה כדי שלא ישכח להתיר הנידוי של בר בי רב אבל עכשיו שמשמת נפשיה מתוך כך שהיה זכור להתיר שלו זכור יהיה נמי להתיר של בר בי רב ור"י פירש דלכפרה היה עושה כך שלא יענש במה שמנדה צורבא מדרבנן כי בקושי יש לנדותו

Do you recall the explanation of today's passage from Rabbi Betzalel ben Avraham Ashkenazi in his commentary called Shitah Mekubetzet with which we opened?  He wrote that in order to coerce the student to confess, Mar Zutra threatened the suspect with...excommunication.  And so perhaps we can now better understand the severity of this coercion, for Mar Zutra himself went to extraordinary lengths to avoid imposing it.

Mar Zutra was a complex man, who would use methods we call torture to extract a confession.  The Talmud also points to his sensitivities.  But do the latter ever forgive the former?

Bava Metzia 2a ~ Garments, Game Theory and the Principal of Contested Sums

בבא מציעא ב,ב

שנים אוחזין בטלית ... זה אומר כולה שלי וזה אומר חציה שלי ...זה נוטל שלשה חלקים וזה נוטל רביע

Two hold a garment; ... one claims it all, the other claims half. ... Then the one is awarded 3⁄4, the other 1⁄4.

We open the new masechet of Bava Metzia with two people claiming ownership of a garment. One claims that it belongs entirely to her, and the other claims he owns half of the garment.  In this case, the Mishnah rules that each swears under oath, and then the garment is divided with 3/4 awarded to one claimant and 1/4 to the other.

Rashi and the Principal of Contested Sums

In his explanation of  our Mishnah, Rashi notes that the claimant to half the garment concedes that half belongs to the other claimant, so that the dispute revolves solely around the second half. Consequently, each of them receives half of this disputed half - or a quarter each.:

זה אומר חציה שלי. מודה הוא שהחצי של חבירו ואין דנין אלא על חציה הלכך זה האומר כולה שלי ישבע כו' כמשפט הראשון מה שהן דנין עליו נשבעין שניהם שאין לכל אחד בו פחות מחציו ונוטל כל אחד חציו

Now of course this is only one way that the garment could be divided between the two claimants. For example, it could be divided in proportion to the two claims, (2/3-1/3), or even split evenly (1/2-1/2).  But instead, and as Rashi explained, the Mishnah ruled using the principal of contested sums. Which is where Robert Aumann comes in.

Game Theory from Israel's Nobel Prize Winner

We have met Robert Aumann before, when we reviewed Israel's glorious winners of the Nobel Prize. For those who need reminding, Aumanm, from the Hebrew University, won the 2005 Nobel Prize in Economics. His work was on conflict, cooperation, and game theory (yes, the same kind of game theory made famous by the late John Nash, portrayed in A Beautiful Mind). Aumann worked on the dynamics of arms control negotiations, and developed a theory of repeated games in which one party has incomplete information.  The Royal Swedish Academy of Sciences noted that this theory is now "the common framework for analysis of long-run cooperation in the social science." The kippah-wearing professor opened his speech at the Nobel Prize banquet with the following words (which were met with cries of  אמן from some members of the audience): 

ברוך אתה ה׳ אלוקנו מלך העולם הטוב והמיטב

If you haven't already seen it, take the time to watch the four-minute video of his acceptance speech. It should be required viewing for every Jewish high school student (and their teachers).

Where was I? Oh, yes. Contested sums.  In 1985, twenty years before receiving his Nobel Prize, Aumann described the theoretic underpinnings of today's Mishnah, as part of a larger discussion about bankruptcy.  His paper, published in the Journal of Economic Theory, is heavy on mathematical notations and light on explanations for non-mathematicians (like me).  Fortunately he later published a paper that is much easier to read and which covers the same material.  The second paper appeared in the Research Bulletin Series on Jewish Law and Economics, published by Bar-Ilan University in June 2002.  "Half the garment" wrote the professor, "is not contested: There is general agreement that it belongs to the person who claimed it all. Hence, first of all, that half is given to him. The other half, which is claimed by both, is then divided equally between the claimants, each receiving one-quarter of the garment." Here is how Aumann visualizes it:

There is another example of this from the Tosefta, a supplement to the Mishnah and contemporary with it. In this new case, one person claims the entire garment, and one claims only one third of it. In this case, the first person gets 5/6 and the second gets 1/6.  

Aumann calls this principal the "Contested Garment Consistent." It turns out that this principal is found in other contested divisions, like a case in Ketuvot 93a, in which a man dies, leaving debts totaling more than his estate. The Mishnah explains how the estate should be divided up among his three wives, each of who has a claim. And it uses the same principal as the one found in today's Mishnah: the Contested Garment Consistent.

משנה, כתובות צג, א

  מי שהיה נשוי שלש נשים ומת כתובתה של זו מנה ושל זו מאתים ושל זו שלש מאות ואין שם אלא מנה חולקין בשוה

היו שם מאתים של מנה נוטלת חמשים של מאתים ושל שלש מאות שלשה שלשה של זהב

היו שם שלש מאות של מנה נוטלת חמשים ושל מאתים מנה ושל שלש מאות ששה של זהב

If a man who was married to three wives died, and the kethubah of one was a maneh (one hundred zuz), of the other two hundred zuz, and of the third three hundred zuz, and the estate was worth only one maneh (one hundred zuz), they divide it equally. 

If the estate was worth two hundred zuz, the claimant with the kesuva of the maneh receives fifty zuz,  while the and the claimants of the two hundred and the three hundred zuz each receive three gold denarii (worth seventy-five zuz).

If the estate was worth three hundred zuz, the claimant of the maneh receives fifty zuz, the claimant of the two hundred zuz receives a maneh (one hundred zuz) and the the claimant of the three hundred zuz receives six gold denarii (worth one hundred and fifty zuz)…

Aumann likes to think of it this way:

Here is how he explains what is going on in the Mishnah in Ketubot.

We’ll call the creditor with the 100-dinar claim “Ketura,” the one with the 200, “Hagar” and the one with the 300, “Sara.” Let’s assume, to begin with, that the estate is 200. As per [the table above], Ketura gets 50 and Hagar 75 – together 125. On the principle of equal division of the contested sum, the 125 gotten by Hagar and Ketura together should be divided between them in keeping with this principle. ... In other words, the Mishna’s distribution reflects a division of the sum that Hagar and Ketura receive together according to the principle of equal division of the contested sum...
The division of the estate among the three creditors is such that any two of them divide the sum they together receive, according to the principle of equal division of the contested sum. This precisely is the method of division laid down in the Mishna in Bava Metzia that deals with the contested garment. 

There's a lot more to the paper, including an interesting proof of the principal using fluids poured into cups of different sizes.  But I prefer to focus on another aspect of the paper.  Prof. Aumann notes that, in addition to its own internal logic, the underlying principal of contested sums fits in well with other talmudic passages. 

The reader may ask, isn’t it presumptuous for us to think that we succeeded in unraveling the mysteries of this Talmudic passage, when so many generations of scholars before us failed? To this, gentle reader, we respond that the scholars who studied and wrote about this passage over the course of almost two millennia were indeed much wiser and more learned than we. But we brought to bear a tool that was not available to them: the modern mathematical theory of games.

The actual sequence of events was that we first discovered that the Mishnaic divisions are implicit in certain sophisticated formulas of modern game theory. Not believing that the sages of the Talmud could possibly have been aware of these complex mathematical tools, we sought, and eventually found, a conceptual basis for these tools: the principle of consistency. Of this, the sages could have been, and presumably were, aware. It in itself is sufficient to yield the Mishnaic divisions; and it is this principle that we describe below, bypassing the intermediate step – the game theory.

It’s like “Alice in Wonderland.” The game theory provides the key to the garden, which Alice had such great difficulty in obtaining. Once in the garden, though, Alice can discard the key; the garden can be enjoyed without it.

What a wonderful analogy. Game theory is the key to entering the garden, a key which might not have been available to earlier generations who learned the Talmud. How lucky we are.  

Happy learning, and שנה טובה, a happy New Year from Talmudology.

Bava Kamma 115b ~ Drinking Snake Venom

בבא קמא קטו, ב

והתניא מים שנתגלו הרי זה לא ישפכם ברשות הרבים ולא יגבל בהן את הטיט ולא ירבץ בהן את הבית ולא ישקה מהם את בהמתו ולא בהמת חבירו

It was taught in a Baraisa: water that was left uncovered should not be spilled out in a public area, nor should one knead clay with it, nor should one lay in the dust with it, nor should one give it to his animal, nor the animal of his friend, to drink. (Bava Kamma 115b)

Don't Drink That Water!

The rabbis of the Talmud were very worried indeed about the health effects of water that had been left uncovered.  This concern was codified by Maimonides, and later by Ya'akov ben Asher (d. 1340) in his famous halakhic work called the Arba'ah Turim. 

טור יורה דעה הלכות מאכלי עובדי כוכבים סימן קטז 

דברים האסורים משום סכנה
  יש דברים שאסרום חכמים משום סכנה כגון משקין שנתגלו שיש לחוש שמא שתה מהן נחש והטיל בהן ארס אפי' אם שתו מהן אחרים ולא הוזקו אין לשתות מהן  שיש נחש שהארס צף למעלה ויש שארס שלו מפעפע עד אמצעית המשקה  ויש שהארס שלו שוקע לשולי הכלי לפיכך אפי' שתו ממנו אחרים ולא הוזקו אין לשתות מהן דשמא ארס של הנחש ששתה מהן שוקע ואלו המשקין שיש בהן משום גילוי מים יין חלב ודבש ושום כתוש 

Tur, Yoreh De'ah 116. Things that are Prohibited Because they are Dangerous

There are things that the rabbis of the Talmud prohibited because they are dangerous. For example, liquids that were left uncovered, because of the possibility that a snake drank from the water and expelled some of its poison into them. Even if others had drunk from the liquid, and not been injured, one should not drink from them.  For some snake venom floats on the surface, and some sinks to the middle and some moves to the edges of the vessel. Therefore, even if others had drunk and had suffered no harm, one should not drink from them, for perhaps the venom from the snake that had drunk the water had sunk to the bottom. The following liquids should not be drunk if they were left overnight in an uncovered vessel: water, wine, milk, honey, and crushed garlic...

The normative Code of Jewish Law, the שולחן ערוך agreed, but added an important caveat:

שולחן ערוך יורה דעה הלכות מאכלי עובדי כוכבים סימן קטז סעיף א 

משקים שנתגלו, אסרום חכמים דחיישינן שמא שתה נחש מהם והטיל בהם ארס. ועכשיו שאין נחשים מצויים בינינו, מותר

The rabbis forbade drinking from liquids that were left uncovered,. They were concerned that a snake may have drunk from them and expelled some of its poison into them. But now that snakes are not commonly encountered, this is permitted. (Shulchan Aruch Yoreh De'ah 116:1)

So today it is permitted for us to drink from an uncovered pot, but only in a place that does not have a problem with poisonous snakes.  Which is not helpful. There are poisonous snakes in nearly every state in the US, resulting in about 2,000 human envenomations each year, and we have noted before that Israel has its own problem with snakes, including the Palestinian Viper.  The World Health Organization estimates that snakes kill between 20,000 and 94,000 people per year. So exactly where this leniency of the Shulchan Aruch might apply is not clear.

But is drinking snake venom indeed dangerous? Maybe not. In 2012 India Today reported that police in New Delhi had seized about half a liter of snake venom to be used "in high-end raves planned for Valentine's Day in and around the national capital." Apparently the venom, when ingested, produces a euphoric state. Who knew?

Video evidence - Drinking Cobra Venom

It is really hard to find any peer-reviewed scientific studies about people drinking snake venom, because, um, it's a silly thing to do.  But that doesn't mean it hasn't been done. So where could we turn to find people doing silly things? YouTube of course. (Warning. This video involves spitting. Not by the snakes.)

Want more? Ok then. Here's another one. This time it involves drinking the venom directly from spitting snake. Apparently, these kind of human interest stories are popular in India. 

Why it is safe to drink snake venom

If you are a diabetic and take insulin, or know someone who does, you may have wondered why the drug has to be injected. It would, after all, be much less bothersome to swallow an insulin pill than to inject insulin several times a day.  The reason is that insulin is a protein, and like all proteins, it is easily broken down by heat and, more importantly, by the acid environment in the stomach.  Our gastrointestinal tracts evolved to break down proteins into their building blocks - and they perform a wonderful job doing precisely that.

Like insulin, snake venom is a complex protein. And so, like insulin, it too is easily broken down in the very acidic environment of your stomach.  Of course, if intact venom gets into your bloodstream, it could kill you. But if you drink venom, then the intact protein never does get into your bloodstream. You don't need to be an Indian snake charmer to safely drink snake venom. You just need a working digestive system.

HOW SNAKES DRINK

 In case you were wondering how we know how snakes drink, here is a diagrammatic view of the apparatus used to record the kinematics and water transport during drinking. The video camera was placed to the left. LED, light-emitting diode. From Cundall, D. Drinking in snakes: kinematic cycling and water transport. The Journal of Experimental Biology. 2000; 203, 2171–2185.

The Talmud was concerned that snakes leave venom in water from which they drank, and that a person drinking from that water would then suffer from envenomation. As we have seen, this concern has no biological basis, although theoretically, if there was an open cut or ulcer in the mouth, ingested venom could get into the bloodstream and then cause its havoc.  But there is another reason why the talmudic concern is overstated.  Snakes, you see, don't leave any venom when they drink water.  As you may have noted from watching the first video, it takes a lot to get a snake to expel its venom - like sticking a blue pen in its mouth.  Venom is a snake's most precious commodity, and it has evolved to protect that commodity. Snakes only release venom when they are in danger, or ready to strike their prey, and not otherwise. Want a great example? The venomous rattlesnake. That species has evolved a warning rattle to tell would-be predators that if they get any closer, they will be bitten. This only makes evolutionary sense if it was in the snake's best interest to do everything possible to conserve its venom.

In a fascinating article on how snakes drink published in The Journal of Experimental Biology, David Cundall notes that a snake's tongue does not carry or move water, and that "in many snakes, the tongue does not visibly move during drinking." That leads to the conclusion that snakes are suction drinkers. And that makes them even less likely to leave any venom behind in the water.

“As far as is known, all snakes are suction drinkers, and the only critical structural variations that might be predicted to influence drinking performance are the relative dimensions and shapes of the mandibles and their suspensorial elements and the arrangements of intermandibular muscles and connective tissues.”

— Cundall, D. Drinking in snakes: kinematic cycling and water transport. The Journal of Experimental Biology. 2000; 203, 2171–2185.

So let's put this all together:

1. Snakes don't release their venom unless they are threatened or hunting. 

2. Snakes use suction when they drink water. Their mouths are not open, which is needed when they are expelling venom.

3. Snake venom is not dangerous when drunk.

4. (If somehow venom did get into the water, it would be greatly diluted.)

So there is no danger if you were to drink from water from which a venomous snake had drunk. None.

Rashi's Two Explanations of Today's Passage

In today's page of Talmud, we are warned not to drink water left standing, because of the danger of a venomous snake having drunk from it.  That danger, as we have seen, does not exist.  But the Talmud also warns us not to use this water to sprinkle on a dirt floor to keep the dust down. According to Rashi, the concern is that a person might cut her foot on a sharp stone left on the floor, which would then allow the venom that was in the water that was sprinkled on that floor to enter the bloodstream. Now that is an incredibly unlikely event, but it is certainly possible, and Rashi's point is absolutely correct. The danger is only if there is an open wound that would allow the venom to enter the blood stream. (שלא יעבור עליהם אדם יחף ויכנס ארס של נחש ברגלו ע"י מכת צרור וימות.)  It is fascinating to compare Rashi's explanation here with his explanation of the the identical passage found in Avodah Zarah (30b).  

 לא ישפכם: שמא יעבור אדם יחף ויעמוד הארס בין קשרי אצבעותיו וכיון שנכנס מעט ונוקב   בבשר שוב אין לו רפואה. רשי, עבודה זרה ל, ב

There, Rashi notes that if "venomous" water was sprinkled on the floor, a person might step on it and absorb the venom through the skin of his toe joints. Once that happens, "שוב אין לו רפואה" - there is no medical treatment. What Rashi may not have known is that snake venom is not dangerous if it gets on your skin, because it is not absorbed from there into the bloodstream.  So his explanation in Avodah Zara is not correct, unlike his explanation of the passage in today's daf.

Bye Bye Bava Kamma

And that brings us to the end of Talmudology on Bava Kamma, which we will finish learning next Tuesday. We've discussed all kinds of topics:

Whether wolves can be tamed

Whether donkeys could break pottery with their braying

The talmudic and legal liability for dog bites

Whether a man is liable for injuring his wife during intercourse

How animals feel pain

Liability in bullfighting

Deaths from falling

Whether a goose has a scrotum

Whether kosher and non-kosher animals might cross-breed

Whether garlic is good for you

Whether honey is bad for you

How animals faced trial

And more besides.  Now it is time to turn to the next tractate. I'll see you on the opening page of Bava Metziah,  when we will discuss game theory and the work of the Israeli Nobel prize winner Robert Aumann.