The ability to respond to the Buddha’s teaching is not the same for all sentient beings; it depends on their aspirations and desires. The teachings of the Noble One rely on these transformational conditions and thus are different for each person. A Sūtra says, “From the night the Buddha realized the Path until the night of his final Nirvāṇa, the doctrine that he preached was true and not vain wisdom.” In reverently examining the gist of the teachings, it is [seen to be] profound and worthy of reliance; therefore it is summarized as the Four Teachings and classified into the categories of tentative and real.