When I was growing up, in the early 1970’s, I heard a song played on the radio called “Family Affair.”   The lyrics began as follows:

 
One child grows up to be
Somebody that just loves to learn 
And another child grows up to be 
Somebody you'd just love to burn 
Mom loves the both of them 
You see it's in the blood 
Both kids are good to Mom 
'Blood's thicker than mud'

      This “Different Strokes for Different Folks” attitude is definitely not the one that the Torah has regarding the family of Isaac, and his two sons Jacob and Esau.

Genealogy alone is not sufficient to attain entry into the rank of the patriarchs of the Jewish nation. Moreover, our tradition states that it was not simply an arbitrary, capricious “will of God” that determined that Jacob and not Esau should receive the blessings. Moral uprightness is also a sine qua non for entry into the ranks of the Avot.
That is why Rebecca, who perceived the moral superiority of Jacob, did not love them both. She ensured that Jacob, and not Esau, would be the recipient of the blessings of Isaac.

      At what point in their lives did the paths of the two twins Jacob and Esau diverge? Alternatively, one may ask this question in the following manner: When did Esau begin to turn out so badly? There are different views in Midrashim and rishonim on this score. (R, Menachem Mendel Kasher, zatzal, in his magisterial Torah Shelemah, quotes quite a number of them.) The most famous view is that of Rashi, following Bereshit Rabbah, who writes that even in the womb, when Rebecca passed a house of idle worship, Esau started to “kick.” For his part, Don Isaac Abravanel, in his commentary to Chapter 25 of Genesis, writes that God preordained that instead of having twin boys that were similar in character traits, Isaac and Rebecca would have two children who were polar opposites, in the moral/religious sense as well as in the physical sense. Why did the hashgahah ha-elyonah decree that this should be the case, asks Abravanel?  Quoting R. Judah Ha-Levi’s Kuzari, who notes that children often resemble (both physically and morally) their grandparents and not their parents (Kuzari claims that an example of this is Abraham, who did not inherit the defective nature of his father Terah but the good nature of  his ancestor Eber), Abravanel notes that Rebecca’s father Bethuel was indeed a wicked person. Thus, there was a mixture of good and bad in the genetic makeup of Isaac and Rebecca’s children. (Of course, Abravanel did not have the modern understanding of genetics, but the point is clear.) On the one hand there was Abraham, who was not only the first monotheist, but who also possessed a sterling, refined, upright nature. On the other side, there was the defective, deceitful and devious nature of Bethuel, who was an idolater to boot (Abravanel adds that these traits certainly expressed itself in Laban’s flawed character). God did not want that the offspring of Isaac and Rebecca should be two morally intermediate children. He did not want the patriarchs to be benonim- average, mediocre figures. Hence, God manipulated the genetic material to ensure that all the good qualities should be encapsulated in only one of the twins, namely, Jacob. Consequently, Jacob possessed a pure nature similar to that of his father and paternal grandfather. Esau, on the other hands, turned out like his maternal uncle and grandfather. Thus, the purity of the patriarchal line was preserved in the person of Jacob. The upshot of his remarkable view, of course, is that Esau was fated to be bad. The entire lives of Jacob and Esau were merely the instantiation of a drama that had already been preordained. This view, of course, rejects the Maimonidean notion of free will or free choice that asserts that one chooses his or her moral destiny. On the other hand, the view that Esau became wicked only after the death of his grandfather Abraham, when he and Jacob were fifteen, implies that he was not fated to do so. Esau’s descent into wickedness was his own fateful choice.

      Perhaps the polar opposite of Abravanel’s view can be found in a work of the Hasidic master Reb Chaim of Tchernovitz (1760-1817), who was a disciple of the Maggid of Mezritch and of Rabbi Yechiel Michel of Zlotchov. He authored Be'er Mayim Chayim ("Well of Living Waters"), a commentary on the Torah. (One should not confuse this Hasidic figure with Professor Chaim Tchernowitz
(1871-1949). This latter figure was known as Rav Tza‘ir and was the author of Toledot Ha-Posekim.) The Be’er Mayim Chaim suggested that the moral collapse of Esau, which legitimated the divine rejection of Esau in favor of Yaakov, occurred only on the very day that Jacob bought the birthright from him. Moreover, it was exclusively due to Esau’s illegitimate sexual relations with a betrothed woman on that day. The corollary of this view, of course, is that
up until that day, it was indeed in the power of Esau to change his ways and to indeed be a legitimate descendant of Abraham and Isaac, and perhaps even to be considered a patriarch. Esau’s fate was not “sealed in stone.” He, through his own reprehensible behavior, caused his own downfall.

      Maimonides’ words in Hilkhot Teshuvah seem appropriate to a consideration
of the approach of the Be’er Mayim Chaim.

Free Will is bestowed on every human being. If one desires to turn towards the good way and be righteous, he has the power to do so. If one wishes to turn towards the evil and be wicked, he is at liberty to do so. And thus it is written in the Torah, “Behold, the man is become as
one of us, to know good and evil” (Genesis 3:22) - there being no other species like it in the following respect, namely, that man, of himself, and by the exercise of his own intelligence and reason, knows what is good and what is evil, and there is none who can prevent him from doing that which is good or that which is evil. And since this is so (there is reason to fear) “lest he put forth his hand etc. (ibid.).”

Let not the notion, expressed by foolish Gentiles and most of the senseless folk among Israelites, pass through your mind that at the beginning of a person’s existence, the Almighty decrees that he is to be either righteous or wicked. This is not so. Every human being may become righteous like Moses, our teacher, or wicked like Jeroboam, wise or foolish, merciful or cruel, niggardly or generous, and so with all other qualities. (Hilkhot Teshuvah 5:1-2)

      And in light of the above discussion, we can add the following: good like our forefather Jacob, or bad like Esau the wicked. May we always have the wisdom and foresight to choose the good.