The final day of Chanukah is customarily called Zos Chanukah, “This is Chanukah.” Since Jewish custom is itself Torah and the entire eighth day of Chanukah is termed “This is Chanukah,” we understand that this day is Chanukah. The last day of Chanukah encapsulates all of Chanukah.
Beis Hillel and Beis Shammai had differing views on how to light the Chanukah menorah. Beis Shammai ruled that the lights should be lit in descending order (eight lights on the first night, decreasing each night), while Beis Hillel ruled that the lights should be lit in ascending order (beginning with one light on the first night and increasing each night).
Beis Hillel and Beis Shammai disagreed about the manner in which the lights should be kindled, because they had two very different ways of looking at matters. Beis Shammai was of the opinion that we look at matters as they are in their potential state, so according to his ruling, eight lights are lit on the first night of Chanukah, for the first day encompasses the potential of all of the days of Chanukah to follow. Beis Hillel was of the opinion that we look at matters as they are in actuality, so according to his ruling, the number of lights lit are in accordance with the actual number of days of Chanukah – one light on the first day, since it is actually only the first day of the festival.
Our Sages relate that the word (Chanukah) is an acronym for (Eight lights are to be lit, and the law is in accordance with the opinion of Beis Hillel.) Since the name of the holiday emphasizes the opinion of Beis Hillel, it clearly indicates that, on Chanukah, we place particular emphasis on the actual rather than on the potential.
What is it about Chanukah that emphasizes the superiority of the actual over the potential? Beis Shammai is focused on the potential of Chanukah. They see the vast amount of light that Chanukah has to offer. They understand how accessing this light can inspire and elevate any Jew. In his mind, you start with eight candles, because eight lights is what Chanukah has to offer.
Beis Hillel, on the other hand, is coming from a more earthy perspective. He appreciates that Chanukah has a lot of light to offer, but prefers not to assume in advance the impact of this light, rather, to take it as it goes, one light at a time. Beis Hillel focuses on the Mitzvah as it is actually being realized, on this day, in this world, by an imperfect created being.
This approach is most appropriate for Chanukah, which is of human, Rabbinic origin. Chanukah is all about the individual who is celebrating it. It’s less about what the experience has the potential to offer, and more about the actual experience of one observing the holiday.