Resolving a contradiction by distinguishing cases

In his words

Tosfos' resolution is a classic move: the Mishnah's items fell from their owner (derech nefilah), so he never knew how many he had and number can't identify them; the Braisa's bundles were put down and forgotten (derech hinuach), so he knows the count. He states the principle behind it: we know that a sign is only as valuable as it is to the knowledge of its owner. 8:00

Then he checks the distinction against the facts: you carry a bundle of needles in your hand. He put it down and he walked away. 10:49

Worked example from a class

JLE, 7:45 to 11:00: falling versus putting down, how you could tell by looking (scattered or neatly placed), and why it's not a contradiction after all.

Hear him teach it

65 moments found so far in 63 transcribed classes; more appear as transcription continues. Tap one to play from that moment.

1. Westwood · Beginner class, Jan 9, 2012 · 45:14“So first take care of the problem, explain the Mishnah clear, get rid of that problem, put it in its place and then we'll see if it's a Tashmah or not a Tashmah.”Resolve the source's internal contradiction before using it as a proof.
2. Westwood · Beginner class, Jan 11, 2012 · 22:29“Is it a contradiction? No, it can't be a contradiction. So what's going on? So you work it through.”When a Mishnah's beginning and end seem to clash, you work out what distinguishes them.
3. Westwood · Beginner class, May 14, 2012 · 34:35“And he brought a contradiction that is inherent in that possuk”Rav Papa's contradiction between the written and read forms of the pasuk.
4. Westwood · Beginner class, May 16, 2012 · 22:06“They're not a contradiction to each other. Active and passive are not a contradiction to each other.”Rav Papa reconciles the written and read forms: passive works only if it imitates active.
5. Westwood · Advanced class, May 20, 2012 · 31:09“It's a contradiction from the beginning to the end.”Rashi's opening (it became mamon) seems to contradict his ending (it is not making oneself wicked). The Ritva resolves this with the idea of a mamon born from a knas.
6. Westwood · Beginner class, Jun 4, 2012 · 46:03“The contradiction came from you. So they talk about that inherent contradiction”Points out the apparent contradiction in Rabbi Yitzchak's reasoning about fallen fruits.
7. Westwood · Beginner class, Jul 4, 2012 · 32:38“Something wrong with what we learned about figs and olives and carobs.”Raises the conflict with the earlier ruling that non-splattering fruit is not abandoned, and resolves it via the Rambam or a special-case reading.
8. Westwood · Beginner class, Jul 9, 2012 · 17:43“that's how we put those two Gomorrahs together. They shouldn't contradict each other.”Reconciles the bug answer with the earlier olives/carobs ruling by distinguishing the cases (sweet dates vs a bug-free place).
9. Encino, Jan 1, 2013 · 47:00“So we have an internal conflict between the beginning and the end, right?”The reisha supports Rava and the seifa supports Abaye; he discusses whether to assume two authors.
10. Westwood · Advanced class, Jan 2, 2013 · 45:01“We need to see a strong connection between the two cases, and supposedly, whatever is the contributing factor to what makes it forbidden by the neck hole”A challenge works only if the same factor (tikkun kli) is present in both cases with opposite rulings.