The tathagatagarbha doctrine is a type of Buddhist philosophy. It teaches that all living things have something called "Analogous Body", or "Essence of the Tathagata", which is the Buddha nature inside of them. It means that everyone can become a Buddha- like person if they cultivate good qualities, like kindness, compassion, and wisdom. In other words, we all have the potential to become Buddhas, to become enlightend and reach Nirvana, the perfect peaceful state of being.