Tathata (Sanskrit, Pali तथता tathatā; Chinese: 真如) is variously translated as "thusness" or "suchness". It is a central concept in Buddhism, and is of particular significance in Zen Buddhism. The synonym dharmatā is also often used.
While alive the Buddha referred to himself as Tathagata, which can mean either "One who has thus come" or "One who has thus gone", and interpreted correctly can be read as "One who has arrived at suchness". Tathatā as a central concept of Buddhism expresses appreciation of the true nature of reality in any given moment. As no moment is exactly the same, each one can be savored for what occurs at that precise time, whether it is thought of as being "good" or "bad".
In the early texts, it is described as an aspect of nibbānā.
In Zen stories, Tathatā is often best revealed in the seemingly mundane or meaningless, such as noticing the way the wind blows through a field of grass, or watching someone's face light up as they smile. According to Zen hagiography, Shakyamuni Buddha transmitted the awareness of Tathata directly to Mahakasyapa in what has come to be rendered in English as the Flower Sermon. In another story, Shakyamuni asked his disciples "How long is a human life?" As none of them could offer the correct answer he told them "Life is but a breath". Here we can see the Buddha expressing the impermanent nature of the world, where each individual moment is different from the last. As Molloy states, "We know we are experiencing the 'thatness' of reality when we experience something and say to ourselves, 'Yes, that's it; that is the way things are.' In the moment, we recognize that reality is wondrously beautiful but also that its patterns are fragile and passing."
The natural beauty of the world, and the importance of nature that surrounds us is a key theme in Buddhism. When asked what Zen is, many masters have answered in relation to the features surrounding them: "The bamboo forest, blue skies above the high mountain", etc. Such answers are given to indicate to us that while we are seeking some mysterious answers above and beyond our own understanding of the world, the true way is there for us to see at any moment right in front of our eyes. The zen master Thich Nhat Hanh wrote "People usually consider walking on water or in thin air a miracle. But I think the real miracle is not to walk either on water or in thin air, but to walk on earth. Every day we are engaged in a miracle which we don't even recognize: a blue sky, white clouds, green leaves, the black, curious eyes of a child--our own two eyes. All is a miracle."
The term Tathatā in the East Asian Mahayana tradition is seen as representing the base reality and can be used to terminate the use of words. A 5th century Chinese Mahayana scripture entitled "Awakening of Faith in the Mahayana" describes the concept more fully: "In its very origin suchness is of itself endowed with sublime attributes. It manifests the highest wisdom which shines throughout the world, it has true knowledge and a mind resting simply in its own being. It is eternal, blissful, its own self-being and the purest simplicity; it is invigorating, immutable, free... Because it possesses all these attributes and is deprived of nothing, it is designated both as the Womb of Tathagata and the Dharma Body of Tathagata."
- The Lankavatara is always careful to balance sunyata with Tathatā, or to insist that when the world is viewed as sunya, empty, it is grasped in its suchness