A non-Jewish man walked into Shammai's study with a straightforward question: "How many laws does Judaism have?" Shammai gave him the honest answer — two. There is the Written Torah and there is the Oral Torah. The man immediately rejected the Oral Torah. He was willing to accept a written text he could read with his own eyes, but tradition passed down by word of mouth? That required trust, and he was not prepared to give it.
Dissatisfied, the man went to Hillel and posed the same question. Hillel gave the same answer: two Torahs, written and oral. The man repeated his objection — he would only accept the Written Torah. Hillel did not argue. Instead, he asked the man to come back the next day.
When the man returned, Hillel began teaching him the Hebrew alphabet. "This is Aleph. This is Beth." The man memorized the letters and left. The following day, Hillel reversed them. He pointed to Aleph and called it Beth. He pointed to Beth and called it Aleph.
The man protested immediately. "Yesterday you told me this letter was Beth!"
Hillel's reply cut to the heart of the matter: "You are relying on my tradition to know which letter is which. If you trust my word for the alphabet, why won't you trust the divine tradition for the Torah?"
The brilliance of Hillel's argument is that it reveals an inescapable truth: every act of reading depends on an oral tradition. Someone taught you what each letter means. You cannot even open the Written Torah without first accepting an unwritten tradition about how to read it. The man who rejected the Oral Torah was already living by it — he just had not noticed.