The Sages of the Midrash read this enigmatic story carefully in an attempt to learn what Man had actually begun to do that evoked so serious a Divine reaction.  They see the text as full of literary allusions to some of man's serious moral and spiritual problems, among them idolatry, arrogance, and callousness.  

One of their comments, though, seems to criticize seemingly innocent, normal activity:  " '[. . . They found a valley in the land of Shinar] and they dwelt there ("vayeishvu sham"). (Bereishit 11:2)' -- Says Rabbi Yitzchak:  Wherever you find dwelling ("yeshiva") the Satan jumps.  Rabbi Chelbo says:  Wherever you find peace of mind the Satan accuses ("mekatreig").  Rabbi Levi says:  Wherever you find eating and drinking the Satan accuses." Eating and drinking, physical consumption, pleasurable experience, is a familiar challenge to the moralist -- just getting involved in that world one often gets sucked in.  But why do yeshiva and peace of mind get the Satan so excited?

"Yeshiva" is, ostensibly, a positive thing: "Increasing 'yeshiva' increases wisdom," says the mishna in Avot (2:7).  "Nachat ruach" also has, for us, very positive connotations: "Happy is he who toils in Torah  . . . and brings 'nachat ruach' to his Creator (Berakhot 17a)."  We are constantly trying to make sure that we give our parents 'nachis'.  Which kind of "yeshiva" should we be involved in, then, and which should we not?  When is the pursuit of "nachat ruach" appropriate and when not?

The Sages go further.  In a number of sources they make similar comments about the expression  "yeshiva" (dwelling), indicating that "yeshiva" in Tanach always (Netziv on Sifrei Parshat Balak Section 1) carries with it a negative connotation.  For example, in Sanhedrin 106a:  "R. Yochanan says, Wherever "vayeishev" appears, it always indicates pain. 
1. 'Israel dwelt ("vayeishev") in the Plains of Moav, and the nation went astray after the daughters of Moav (Bemidbar 25:1).' 
2 'Ya'akov dwelt in the land of his father's sojourning . . . and Yosef brought the negative reports about his brothers.' 
3 'Israel lived in the land of Goshen . . . The days of Yisrael's death approached.'
4 'Yehuda and Yisrael lived securely, every man underneath his grape vine and fig tree . . . Hashem brought an opponent (satan) against Shelomo, Hadad the Edomite of the royal family in Edom.'"

In other sources yeshiva fares no better, either bringing in its wake ruin (Sifrei Balak, Parsha 1), problems (Shemot Rabba 41:7), anger and unease (Bereishit Rabba 84:2), or, most crucial, moral breakdown ("the Satan jumps") (Bereishit Rabba 38:7).  

"Vayeishev", "he dwelt", in Bereishit 37:1 sharply contrasts with the expression "megurei aviv", "his father's sojournings" that follows.  The first implies a sense of permanence, of reaching a resting place, the second indicates merely a temporary stay.  The Midrash (Bereishit Rabba 84:2, quoted by Rashi) comments: "R. Acha says:  When the righteous dwell in tranquility in this world, the Satan comes and accuses, 'Is it not enough that the World to Come is ready for them; they also want to live tranquilly in this world?. . . Yaakov our father wanted to dwell in tranquility in this world, and he was met with the "Satan" of the Yosef episode."Even the righteous (especially the righteous) should not expect tranquility and peace of mind in this world, but should focus on action and work.  Ironically, teaches the Midrash, the moment one settles into a comfortable, unconfronted, placid something unsettling will inevitably occur.

Yaakov's biography had been a series of troubles with his brother, his father in law, with his daughter Dina and his sons Shimon, Levi and Reuven.  He finally reached Eretz Yisrael once again and finally hoped for peace of mind, yet, . . .

This approach is echoed in Pirkei Avot (4:22), "He (R. Yaakov) used to say, 'One moment of repentance and good deeds in this world is better than the whole World to Come, and one moment of peace of mind in the World to Come is better than all of this world."  As the Ramchal (Derekh Hashem 3:3) summarizes, "Existence was split into two periods, one of work (Olam Hazeh -- This World) and one of receiving reward (Olam Haba -- the World to Come).

The four verses quoted by the Talmud in Sanhedrin all are in line with this theme.  Judaism teaches that religious life must remain dynamic and active. Resting with a passive sense of "being there" opens one up to the temptation of the daughters of Moav.  When this-worldly existence becomes static, we are shaken out of it by a crisis, or by a Hadad or a Pharaoh. 

The episode of the Tower of Babel seems out of place in this group, though.  Does not the Torah immediately follow with a record of their activity, almost frenetic, ceaseless activity:  " . . . Let us make brick, and burn them thoroughly . . . Let us build us a city, and a tower, whose top reaches the heaven . . ."?  They immediately began an engineering project that must have occupied a lot of manpower working long hours, both physically and mentally. 

There seem to be two types of activity:  innerly active activity, and external activity that covers up an unhealthy inner life.  The people of the world at that time were building a tower, advancing technologically, but were not developing spiritually and socially.  They were unified, "One language and [speaking] the same words, " but this unity connected up with insecurity -- "Let us make us a name lest we be scattered abroad upon the face of the whole earth." They had serious religious and theological problems that were being dealt with in a pathological way (the Midrash Bereishit Rabba 38 sees them as either warring with God or ignoring Him, rather than establishing a positive, creative relationship with Him,  something that takes inner courage and demands maturity). 

The Sages do not, on any account, diminish the value of work -- "Love work . . ." (Avot 1:10).  They certainly encourage living with joy and happiness (Avot 6:5) and recognize the need for sleep, for refreshing leisure and for a healthy diet.  They also encourage us to give God nachat ruach, but not to try and strive for it in this world.  The sources we have brought, though, decry complacency, this-worldly contentment, and a religious life that is stagnant and static -- trying to reach the final dwelling place while still in this world.  The story of the Tower of Babel teaches that this is further complicated when external activity is used as a way of avoiding a confrontation with inner challenges.  Taking on the challenge of this dynamism is joyous and demands work -- physical, mental, and spiritual.  Yeshiva is also positive when it is connected with Torah, attaching permanence and social unity to that which is eternal and ultimate. 

Two things complicate (and complement) the picture we have presented: 
1.  Shabbat does leave room, even in this world, for rest, for menucha, for a pleasurable Olam Haba-like experience (albeit within the confines of a body and the limitations of this phase of existence.).  
2.  Even The Sages' vision of the experience of the righteous in the World to Come is a dynamic one:  "Said Rabbi Chiyya bar Ashi in the name of Rav, 'The righteous have no rest (Rashi:  from Yeshiva to Yeshiva and from Medrash to Medrash)  neither in this world or in the next, as it says, 'They go from strength to strength and will see G-d in Zion." (Berakhot 64a)