Medicine was medieval and a lot of it still is.

In the Conversations of Rav Nahman [of Breslov] is brought a long tired against doctors. But Rav Aryee Kaplan pointed out that this was  written when even oxygen was unknown. Medicine was medieval, It was all about balancing the four elements. However the same warning of Rav Nahman still applies today There procedures that are time tested and well known. These are okay. But new experimental things are not. My parents warned me not to take any medicine that has not been on the market for at least 50 years.

Medicine is still all about "balancing the four elements" except they use a different terminology in order to hide what they are doing: i.e., correcting chemical imbalances

 Even though to just say the words of what you are studying does not take the place of in depth learning "Iyun", I still think it is important. You can see this in the LeM of Rav Nahman vol I section 74 where he specifically goes into the importance of in depth learning/iyun. This clearly is not meant to disagree with Conversations of Rav Nahman  76 [Sichot HaRan section 76].

And though Rav Nahman meant this for learning of Gemara, it also applies to Math and Physics.

[I have mentioned before that these are called "secular" by mistake. They are not secular, but rather the wisdom of God embedded in the Work of Creation.] you can see this most of all in Mishna Torah of the Rambam laws of Talmud Torah chapter 3 where he brings the law to divide one's learning into three parts: (1) Tenach [Old Testament.] (2) Oral Law (Mishna). (3) Gemara and the Rambam  adds there  "in the category of Gemara are the subjects brought in the first four chapters of Mishna Torah". [Physics and Metaphysics.]

Those four chapters are Aristotelean Physics and Metaphysics

Rambam laws of Robbery 9. Bava Metzia 15 [בבא מציעא ט''ו]

Let's say you have a  case that someone stole a field, then sold it, and then went and acquired it from the owner. The Rambam holds the one who bought it from the thief  now acquires it automatically מה זכה הלוקח מן הגזלן כל זכות שתבוא לידו [Bava Metzia 15] even if the buyer knew it was stolen. Most other Rishonim disagree and hold that if the buyer knew it was stolen, then he does not acquire the field. To the Gra this is the reason for the law in the Shulchan Aruch that if the thief  does not subsequently buy the field (and thus it is taken from the buyer and given back to the owner). then the buyer must get paid back by the thief.  And if the thief has no money then the buyer collects from any property that the thief had but sold (משועבדים).  This is ok if the buyer did not know it was stolen. He is not at fault, and so ought to be paid back.  But what if he did know? Why should the people that bought unrelated property from the thief suffer.  That is the exact point of the Gra. Collecting from that sold property of the thief in fact does not apply. However Rav Shach points out that the Rema disagrees with this, since he has no comment on the Shulchan Aruch that the buyer gets paid back even from sold property [thus also if he knew that it was stolen], and yet brings the other rishonim that if the buyer  knew, then in the case the thief bought the property from the original owner, then the buyer does not acquire the field.\Rav Shach does answer this question on the Rema, but I am having a hard time seeing the answer. [The problem with the bill of sale that the thief gave to the buyer when they both know the field was stolen is it is "forged from within" מזויף מתוכו. It can not be considered a loan when it say openly that document of a sale. And thus the buyer should not be able to get paid for his loss from property that the thief had but sold (משועבדים).

[I should mention that a loan with a document gets paid back even from sold property that was sold after the loan was made; But not from a verbal loan. So in our case, the reason the buyer should be paid back from sold property is because there is a document of sale. But if that document is invalid because both the their and the buyer know that the field does not belong to the thief, the document should be considered invalid.]

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Let's say you have a  case that someone stole a field, then sold it, and then went and acquired it from the owner. The רמב''ם holds the one who bought it from the גזלן now acquires it automatically מה זכה הלוקח מן הגזלן כל זכות שתבוא לידו [בבא מציעא ט''ו] even if the buyer knew it was stolen. Most other ראשונים disagree and hold that if the buyer knew it was stolen, then he does not acquire the field. To the גר''א this is the reason for the law in the שלחן ערוך that if the גזלן  does not subsequently buy the field (and thus it is taken from the buyer and given back to the owner). then the buyer must get paid back by the גזלן.  And if the גזלן has no money, then the buyer collects from any property that the thief had but sold (משועבדים).  This is ok if the buyer did not know it was stolen. He is not at fault, and so ought to be paid back.  But what if he did know? Why should the people that bought unrelated property from the גזלן suffer.  That is the exact point of the גר''א. Collecting from that sold property of the גזלן in fact does not apply. However רב שך points out that the רמ''א disagrees with this, since he has no comment on the שלחן ערוך that the buyer get paid back even from sold property [thus also if he knew that it was stolen] and yet brings the other ראשונים that if the buyer  knew then in the case the thief bought the property from the original owner, then the buyer does not acquire the field.\רב שך does answer this question on the Rema, but I am having a hard time seeing the answer. [The problem with the bill of sale that the גזלן gave to the buyer when they both know the field was stolen is it is "forged from within" מזויף מתוכו. It can not be considered a loan when it say openly that document of a sale. And thus the buyer should not be able to get paid for his loss from property that the thief had but sold (משועבדים).

However רב שך can answer and say that then even if the buyer did not know the field was נגזל the document should also be considered "forged from within" מזויף מתוכו. And yet the שלחן ערוך decided that the buyer can get paid back from property that the גזלן sold.

[I should mention that a loan with a document can be repaid even from sold property that was sold after the loan was made (משועבדים); But not from a  loan בעל פה . So in our case, the reason the buyer should be paid back even from sold property is because there is a document of sale. But if that document is invalid because both the גזלן and the buyer knew that the field does not belong to the גזלן, the document should be considered as invalid.]

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נניח שיש לך מקרה שמישהו גזל שדה, ואז מכר אותו, ואז הלך ורכש אותו מהבעלים. הרמב''ם מחזיק את מי שקנה ​​אותו מהגזלן עכשיו רוכש אותו אוטומטית. מה קנה הלוקח מן הגזלן כל זכות שתבוא לידו [בבא מציעא ט''ו] אפילו אם הקונה ידע שהוא נגנב. רוב ראשונים חולקים וגורסים שאם הקונה ידע שהוא נגזל, אזי הוא אינו רוכש את השדה. לגר''א זה הטעם לדין בשלחן ערוך שאם הגזלן לא יקנה אחר כך את השדה (וכך הוא נלקח מהקונה ומוחזר לבעלים). אז הקונה חייב לקבל תשלום בחזרה על ידי המוכר. ואם אין לגזלן כסף, אז גובה הקונה מכל נכס שהיה לו אבל מכר (משועבדים). זה בסדר אם הקונה לא ידע שהוא נגנב. הוא לא אשם, ולכן צריך להחזיר לו. אבל מה אם הוא כן ידע? למה האנשים שקנו נכס לא קשור מהגזלן צריכים לסבול? זאת בדיוק הנקודה של הגר''א. גבייה מאותו נכס שנמכר של הגזלן למעשה אינה חלה. אולם רב שך מציין שהרמ''א חולק על כך, שהרי אין לו הערה על השלחן ערוך שהקונה מקבל תשלום אפילו מנכס שנמכר [וכך גם אם ידע שהוא נגנב] ובכל זאת מביא את הראשונים שאם הקונה ידע אז במקרה שהגנב קנה את הנכס מהבעלים המקורי, אז הקונה לא רוכש את השדה. רב שך אכן עונה על שאלה זו ברמ"א, אבל אני מתקשה לראות את התשובה . [הבעיה בשטר המכירה שהגזלן נתן לקונה כששניהם ידעו שהשדה נגנב היא שהוא "זיוף מבפנים" מזויף מתוכו. זה לא יכול להיחשב כהלוואה כאשר זה אומר בגלוי כי הוא מסמך מכירה. ולפיכך לא יוכל הקונה לקבל תשלום על הפסדיו מנכס שהגנב אך מכר (משועבדים

אולם רב שך יכול לענות ולומר שאז גם אם הקונה לא ידע שהשדה הוא נגזל יש לראות במסמך גם "מזוייף מבפנים" מזויף מתוכו. ואף על פי כן החליט השולחן ערוך שהקונה יכול לקבל כספו בחזרה מהנכס שמכר הגזלן

אזכיר כי הלוואה עם מסמך ניתנת להחזר גם מנכס שנמכר לאחר מתן ההלוואה (היינו ממשועבדים); אבל לא מהלוואה בעל פה. אז במקרה שלנו, הסיבה שהלוקח יכול לגבות אפילו מנכס שנמכר היא בגלל שיש מסמך מכירה. אבל אם מסמך זה פסול כי הן הגזלן והן הקונה ידעו שהשדה אינו שייך לגזלן, יש לראות המסמך כפסול

With the Rambam and Saadia Gaon, Aristotle gained prominence. [Ibn Gavirol was Platonic]. But the problem with Aristotle was that there is no "form" of the fire that gets into the head to make us know what "hot" is. And as Kelley Ross pointed out, DNA  became understood as a way for plants to grow into their final form a different from the forms of Aristotle. So some new thinking became needed to understand Torah in the light of more modern questions. The difficulties of a reconciliation between Reason and Faith  need a different approach. One might just go back to Plato  and Neo-Plato [Plotinus].

 

I am not absolutely completely against kabalah. A lot depends on when and how  and what. For example i hold strongly with the Ari --Isaac Luria and with a few other mystics like R Avraham Abulafia. Even the Zohar I hold like Rav Yaaov Emden that studied the  of its authenticity and came to the conclusion that some parts of it were derived from ancient source while a lot was written during the middle ages [as you can see easily from the phrase im kal da a translation of im kal ze which was invented by Ibn Tibon

In fact the different great mystics after the Ari I learned a lot from, Rav shalom sharabi, rav yakov abukazeira, the Gra and Moshe Chaim Lutzato 

Ultra religious Jewish teaching is derived from the teachings of Shabtai Zvi and Natan the false prophet.

 The importance of musar [books on Torah ethics written during the middle ages] is that without it it is impossible to gain any sort of correct idea of what the values of Torah are. What you get without musar is religious fanaticism or an array of  assorted delusions.

 The Middle Ages were much more rigorous in defining Torah values.

One reason for this that books of Torah ethics during the middle ages were logically derived from the Oral Law [Talmud] and Written Law. Books that were written later generally are derived from mysticism. some of that might be ok to some degree. But most often it is derived from the teachings of shabtai zvi and Natan the false prophet. I do not like to go into this in detail but the material is readily available to anyone who want to look up the sources.

[Once mysticism gets mixed with Torah, things tend to go downhill.  ]