 Others, like Crescas and David ben Samuel Estella, spoke of seven fundamental articles, laying stress on free-will.On the other hand, David ben Yom-Tob ibn Bilia, in his "Yesodot ha- Maskil" (Fundamentals of the Thinking Man), adds to the 13 of Maimonides 13 of his own — a number which a contemporary of Albo also chose for his fundamentals; while Jedaiah Penini, in the last chapter of his "Behinat ha-Dat", enumerated no fewer than 35 cardinal principles.Isaac Abarbanel, his "Rosh Amanah", took the same attitude towards Maimonides' creed.