JPost by Rabbi Levi Cooper [The question remains - is it only children that should avoid higayon or also mature Torah students?]
When Rabbi Eliezer's health was failing, his students paid him a visit (B. Berachot 28b): "Our master, teach us the ways of life that we may merit through them the life of the world to come," they implored their teacher. Rabbi Eliezer offered them parting advice: "Be mindful of the honor of your peers, and keep your children from higayon, and place them between the knees of Torah scholars, and when you pray know before whom you stand - and on account of this you will merit the life of the world to come." A legacy relating to interpersonal relationships and to our connection with God.
What, however, is this higayon that we should steer our children away from? Over the ages our commentators have offered different explanations of this obscure term. The earliest attempts to translate higayon refer to the art of rhetoric taught by the Greek sophists of the fifth century BCE (Hai Gaon, 10th-11th centuries, Pumbedita). The sophists taught that the search for truth was of secondary importance and trained their charges with the ability to persuade the masses of whatever they wished them to believe. Such an education prepared the youth for the world of Greek politics, where being clever and smart was often more valuable than being truthful and earnest. Some sophists even claimed that knowledge was unnecessary for the art of forming a cogent argument or offering an unassailable reply. According to this approach, Rabbi Eliezer was discouraging this discipline which went contrary to the more lofty goals of Torah study.
A number of later commentators, who were far removed from Greek culture, suggested that higayon refers to aspects of the study of Bible. According to one such approach, Rabbi Eliezer was imploring his students not to overly focus on Bible which draws the heart (Rashi, France, 11th century). It appears that Rabbi Eliezer was afraid that the attractive literary biblical style would be so inviting that youth would not progress to the more difficult subjects of Torah study. Indeed, elsewhere the sages declare that the pursuit of Talmud is the loftiest of disciplines, with Bible study being a mere stepping stone toward the distinguished enterprise of discussing and deriving law (B. Bava Metzia 33a).
In a similar yet different vein, other commentators suggested that Rabbi Eliezer was warning against the literal translation of biblical passages, where such a translation would lead to a heretical reading of the text (Rabbi Natan of Rome, 11th century; Meiri, Provence, 13th century). The above suggestions all try to grasp the meaning of Rabbi Eliezer's statement by seeking the connotation of the key word - higayon.
One commentator, however, suggests that instead of focusing on this elusive term, we should look to Rabbi Eliezer's legacy to fathom his message (Rabbi Reuven Margoliyot, Lvov-Tel Aviv, 20th century). Elsewhere in the Talmud, Rabbi Eliezer is adamant that tradition must be faithfully transmitted in an unbroken chain reaching back to Sinai (B. Succa 27b).[...]
[Rabbli Eliezer] never stated any ruling that he had not heard from his teachers. He would only transmit traditions that he had received. Returning to our passage and the word higayon - Rabbi Eliezer is suggesting an educational maxim: Not to encourage youth to explore higayon, that is, new disciplines that are not rooted in the tradition or material that has not been passed down from one generation to the next.
This approach can be supported by comparing the last bidding of Rabbi Eliezer with the legacies of other sages. From the tractate Avot we are familiar with sages offering three aphorisms as their ethical will. Rabbi Eliezer would have been familiar with this pattern which dated back to the end of the Second Temple period. Yet when choosing his parting words, Rabbi Eliezer appears to offer four aphorisms: (1) Consciously honoring peers, (2) steering youth away from higayon, (3) raising children among Torah scholars, and (4) knowing before whom we stand. If we understand higayon to be referring to disciplines that have no Torah basis, then the four statements could be read as the traditional three: The first max im refers to interpersonal relationships and the third maxim refers to matters between humans and God. The middle truism relates to passing the legacy to the next generation. With regard to this matter, Rabbi Eliezer suggests that children should be directed away from studies not rooted in tradition and instead be guided toward Torah scholars. Through this three-point program, says Rabbi Eliezer, "You will merit life in the world to come."