halacha - Leather and vegetarianism according to Rav Kook?

According to Rav Kook, it is ideal to be a vegetarian. This is because he assumes G-d would not create a world in which creatures could not exist in harmony (see linked article) and therefore this would include killing animals. How, according to Rav Abraham Isaac Kook in A Vision of Vegetarianism and Peace would the necessary leather and parchment for things like Tefilin or Torah scrolls be obtained?

Answer

Tefilin, etc., can be made from animals that die on their own (see e.g. The source in the Talmud is Shabbos 108a). Thus even under a situation where killing animals wasn't possible, leather would still be available.