Rashi opens his commentary with the question of why the Torah concerns itself with the story of creation – why not begin with the first mitzvah, as ostensibly Torah is a book devoted to a discussion of mitzvos, not history or science. Ramban takes issue with Rashi’s question and argues that without the story of creation is essential to establish our faith in G-d as Creator.
One could explain the machlokes as a dispute over what the text of Torah shebk’sav should incorporate. Rashi might agree that belief in G-d as creator is an essential component of faith, but might see that belief as something which should or could be transmitted through tradition or torah sheba’al peh without necessitating a parsha in chumash. (I think it goes without saying that Rashi does not deny that belief in G-d as Creator is necessary; the mitzvah of Shabbos, among others, is stripped of meaning without that.) Read in this light, Rashi’s conclusion that the parsha is included as a means of justifying the Jewish people’s claim to Eretz Yisrael by virtue of its being gifted to them by G-d, the Creator, is not a philosophical justification for the parsha, but is simply an acceptance of the need for pragmatic public relations.
The Sefas Emes (5636) offers a more philosophical analysis of the machlokes in which he takes a different approach to the Midrashic lesson we learned yesterday about G-d’s offering Torah to Eisav and Yishmael and their rejecting it. Torah exists and can be read on many levels, from being a mystical code which consist completely of G-d’s name, as Ramban writes in his introduction, down to a practical manual that addresses the most mundane details of life. This is the meaning of the Midrash that G-d offered the Torah to Eisav and Yishmael – He created a Torah which can be understood not just by the most exalted saints, but which can even speak to an Eisav or a Yishmael on their level. While R’ Bloch focused on the rejection of Torah by the nations as evidence of its incompatibility with all else except the Jewish soul, Sefas Emes focuses on the hava amina of it being offered to others as a sign of Torah’s universal message.
Using this Midrash as background, Sefas Emes explains the difference between Rashi and Ramban by invoking a dichotomy he discusses in many places – emes vs. emunah, faith vs. truth. Faith is only needed in the absence of certainty or truth, and vice versa, truth, certain knowledge precludes the need for faith.
Rashi is not just addressing the narrow issue of what belongs in the text, but is begging the broader philosophical question posed by Ramban’s premise– why indeed is there a need for a parsha teaching “emunah” in G-d as creator? For the Jewish heart, G-d being the Creator and master of the universe is a truism, emes, and not merely the subject of faith.
Rashi’s answer is that that G-d did not only give us a Torah which presupposes the certainties of knowledge in the Jewish heart; He gave us the same Torah which He had offered to Eisav and Yishmael, a Torah which addresses even those for whom the truth is unclear. This is the meaning of the pasuk in Tehillim which refers to our receiving the “nachalas goyim,” the portion offered to the non-Jews. Existentially, the Jewish heart is predisposed to acknwoledge the emes of ratzon Hashem, but to serve as the conduit of the dvar Hashem to an imperfect world that does not always see the truth, we were given a Torah with teachings of emunah.