The school of Jewish law that advocates increasing the number of candles each night is Beit Hillel. Its ruling begins with one Hanukkah light on the first night and adds one more on each successive night, reaching eight lights on the eighth night.
The debate is recorded in the Babylonian Talmud, tractate Shabbat 21b. Beit Shammai proposed the opposite pattern: begin with eight lights and decrease by one each night. One explanation connects Shammai’s approach with the declining number of bulls offered during Sukkot, while Hillel’s approach follows the principle that holiness should increase rather than decrease.
Jewish practice follows Beit Hillel. The additional shamash, or helper light, is used to kindle the other candles and is not counted among the eight ritual lights. The familiar ascending display therefore represents both the passing days and a growing public reminder of Hanukkah’s miracle.