The term means to have love for the people, and cherish all things in the world. Here wu (物) includes plants and animals, while ai (爱) implies using them in a measured and appropriate way. This was first proposed by Mengzi who differentiated natural emotions as: a love for close family, a broad compassion for other people, and a sense of cherishing for plants and animals. The love could be close or distant, but a person of virtue always begins with love of close relatives, which then extends to other people and eventually to all things in the world. Though this feeling starts within the family, it should extend beyond it, even beyond the human race to include plants and animals, to become a broad love. The goal is to achieve harmony within oneself, with others and with nature. Zhang Zai’s concept that “all people are my brothers and sisters, and all things are my companions” is very similar. 
Mengzi said, “Men of virtue cherish all things but this is not benevolent love, have compassion for others but this is not love of family. Men of virtue love and care for their loved ones, they are therefore kind to other people. When they are kind to people, they treasure everything on earth.” (Mengzi)