The difference between chelev and shuman and how to determine what is permitted

When Rabbis in different locales have different (both authoritative) rulings, how are we to view the truth of those rulings?

can an animal that has to get a surgery and becomes a treifa in the process, be reversed when the doctor sews up the incision?

Are there really any true treifot out there or are we just being stringent?

What is the difference between "glatt" and non-glatt kosher meat?

The spiritual message behind the treifa laws of the animal's brain

The prohibition to "shop" around for halachic rulings

The spiritual and philosophical rationale behind the prohibition of eating "treif"

Do the defining "wounds" that make an animal "treif" change or evolve with scienctific discovery?

If my non-observant neighbor violates Shabbat that ends up benefiting me, am I allowed to gain from their violation of Shabbat?