Al-Biruni and Newton were mathematicians of different religious traditions. Not only were they devotees of different religions, they were also thinkers of different epochs. They grew up in societies having different norms and ideals. Al-Biruni spent his life totally under Muslim governments which by and large follow the Shari'ah. On the other hand, Newton lived in a country in which Christianity was the dominant religion. These differences in cultural and historical background notwithstanding, there are many similarities in their philosophies of mathematics. In what follows, we will examine these similarities as well as pointing out the significance of the commonalities.