The basic mitzvah of Chanukah is to celebrate "the miracle that happened then," by lighting the chanukia for eight days. Interestingly enough, though, there is a dispute in the Talmud between Beis Shammai and Beis Hillel whether to increase the number of candles each day from one to eight, or to start with eight and remove a candle each day for eight days. Although the definitive Halacha rules according to Beis Hillel, who argues that we add a candle each day, it is worthwhile to look at the dispute between Beis Shammai and Beis Hillel for the many insights into Chanukah that it brings to light.
Beis Shammai's rationale for going downward relates to the parim, the bulls, offered as sacrifices on Succos in the Temple, which were offered in descending order from 13 to 7 on each of the 7 days of Succos totaling 70 bulls in all, corresponding to the 70 Nations of the world. There are two dimensions to the parim. One dimension is that we have a concern for the material and spiritual well being of the entire world. (The Talmud tells us that the 70 Nations of the world are in a perpetual state of decline). When we offer sacrifices, we unlock an energy which brings blessings from heaven for the entire world. (If the Babylonians and the Romans who each destroyed the Temples in their own time, had understood what was being achieved for them with the sacrifices, they would have come with guards to protect the Temple rather than come to destroy it). Therefore, this is an expression of concern for the entire world, because, without the energy created by our sacrifices, the world is in a state of decline. The second dimension of the parim sacrifices is to infuse a special nationalistic energy into the Jewish People to remember that they are an elite corps chosen by G-d to be a light unto the Nations, so as to inspire them, and to strengthen their resistance to the negative corrupting pagan influences of the 70 Nations, expressed in the declining pattern of the sacrifices. Thus, lighting the chanukia in descending order would symbolize the decreasing effect that entropy has on the world and the decreasing influence that the 70 Nations have on the Jews.
Unfortunately, the 70 Nations of the world did not understand the nature of the sacrifices in the Temple. As such, the Jewish People have suffered countless pogroms throughout the ages and the destruction of two Holy Temples. Although the Greeks did not actually destroy our Temple, they contaminated it. Chanukah celebrates the return of holiness to the Temple after the contamination of the Greeks. Hence, Beis Hillel argues that since holiness was returned to the Temple, and since we move upward in matters of kedusha, (holiness), then we should light in ascending order to illustrate this increase in kedusha.
Chanukah took place in Israel during the Hellenistic oppression called golus Yavan. This third exile lasted 180 years, and was dubbed the exile of darkness because the Greeks made every effort to make Jews see and understand the world in a way which was alien to the Torah. Darkness, because nothing is as dark as the enslavement of the human mind. The golus Yavan is always referred to as darkness because it took away the light of Torah.
Darkness is the absence of light. Things that are negative we call darkness. They are opposite of good Evil is darkness. But you can combat Evil in the world. You can attack it by fighting whatever is wrong in the world; or, you can create such a tremendous light where you are that the darkness just fades away. Chanukah expresses the victory of light over darkness. But the question lies in what strategy is most successful: to burn away and destroy Evil; or, to create a greater light so that the darkness just vanishes?
Look closely at the nature of a flame. It has two very distinct properties: it can burn, and it can illuminate. In combating Evil in the world, do we destroy it, do we burn it, or do we illuminate Torah creating a greater light in the world to dissipate the darkness? This is the nature of the machlokes, (dispute), between Beis Shammai and Beis Hillel. Both methods are valid, but what is supposed to be the main thrust of a Jew, what is to be learned from what happened in Chanukah?
Beis Shammai and Beis Hillel are both agreed on the purpose of kindling the chanukia - It is to rekindle in ourselves the light of the triumph over darkness. And they both agree that the number of candles should be different each night to signify that each day of the miracle is unique. But its uniqueness can be expressed either by adding or subtracting a candle each day. Beis Shammai learns that when we fight the negative corrupting aspects of the prevalent pagan world-culture either through sacrifices, (or prayer when we have no Temple) we are steadily wiping out their influence on us, which is reflected in the decreasing pattern of the parim sacrifices on Succos. Thus, we should light the chanukia in the same way: starting with eight and reducing the number of candles each night. In this way, the burning quality of the flame symbolizes the diminishing effect that the negative forces of the world have on us, the destruction of Greek paganism, and ultimately the destruction of Evil in the Universe.
On the other hand, Beis Hillel sees the battle against immorality in the world, not as a confrontation, but rather, as an important reason to raise ourselves spiritually, to become the embodiment of morality in the world by living according to Torah principles. This way, the entire world would see us and want to imitate us. So, says Beis Hillel, the more successful method of wiping out darkness, is by increasing the illumination of Torah everywhere, not by burning away Evil, but rather, by increasing our light as a Torah Nation. For this reason we increase the number of candles each night to remind ourselves of our responsibility, as Jews, to steadily increase the light of Torah knowledge and understanding in the world; banishing the darkness of Evil by becoming a light unto the Nations.
When Moshiach comes, all the Nations of the world are going to realize that whatever they did in the world succeeding in enriching themselves, building a world military-power, making scientific discoveries, becoming an economic-power, whatever they are going to see that the point of it all had to do with what impact it would have on the Jews. We're supposed to be "A Light Unto The Nations." That's our own particular G-d given role in the world. That's what light is all about. When we perform as light, when we do something about bringing the light of Torah into the world, that's when there is light! And when there isn't, when we aren't learning Torah or performing mitzvos, when we assimilate, G-d sends us the Babylonians, the Persians, the Greeks, the Romans, the crusaders and the pogromists, Enlightenment and Emancipation, and the Western World, and all the other threats that happened throughout history. They are sent to stimulate us, to wake us up, and to arouse us back to our original purpose.
If we are going to forget our purpose, and if we are going to try to become the 71st Nation of the world, then G-d will stop us. He won't tolerate that. We can't be a 71st Nation because then the entire world will surely sink into the morass of immorality and corruption. There has to be at least one Nation that is pulling everybody up and not copping out of its responsibility. And if we don't do this, then somebody is going to come around and remind us that we're Jews and that we have this responsibility. Why do you think that all the attempts of Jews to become the 71st Nation - to assimilate - have failed? And don't think that they haven't tried hard enough Jews have tried, oh have Jews tried in our time perhaps harder than any other time there has been an attempt of Jews to disguise or to forget their Jewishness and to just blend in to the melting pot, to just blend in with the rest of the world. You know why it has failed? It has failed for one very simple reason: "you can change your Moses, but you can't change your noses." Meaning, you can say all the protestations you want about what you believe, and you can try to dress like them, eat their food, sing their songs, speak their language, and do everything like them, but there is always going to be somebody who will recognize some feature of your Jewishness, and he is going to be the one who reminds you. That is his purpose. G-d sends them to shake us back into a realization of what we're all about and that we can never be part of those 70 Nations because we have a unique role to play in the world.
In the end of days our Sages tell us that there is going to be a world trial, like a post Nuremberg trial, except that there is going to be only one judge: The One Judge; G-d. And G-d will ask the 70 Nations: "what did you do to promote Torah in this world?" And the Talmud says that all the Nations will come forward with their new understanding of world history, and they will try to take credit for having enabled Jews to learn Torah by providing them with such necessities as marketplaces, roads, bridges, and bathhouses. But G-d will reject their claim telling them: "Although your achievements did actually benefit the people of the Torah, it was only because My Divine Plan of World History put you in a position to do so; but, in fact, your motivations were purely selfish ones: either for economic exploitation or physical gratification." In a broader sense, throughout history, the persecution of Jews, although motivated by primitive anti-Semitism, has also been part of The Divine Plan for reminding Jews of their special mission in this world.
Hence when we are lighting our Chanukia this year, we should have in mind that, in our encounter with "darkness", we don't want to use the flame to burn and destroy the world, rather, we want to use it to illuminate the whole world with Torah. We want to light the way for all the Nations so that they can prosper materially and spiritually. The prescription for overcoming "darkness" in our time, is the same as it was in the time of the Hellenistic oppression: by increasing our light. If we increase our learning, and if we increase our holiness, then we will truly be "A Light Unto The Nations."