In Buddhism, one often hears the term Buddha-nature, but there are many definitions for the term Buddha-nature, and it can be very confusing. Some people teach it as some kind of inherent essence for Enlightenment, while others teach that we are already enlightened because we have Buddha-nature.
I feel that the Chinese Buddhist master, Yin-Shun, gives a more thorough explanation in his book The Way to Buddhahood. Here he discusses the view of Buddha nature by the two main threads of Buddhist philosophy, the Madhyamika and Yogacara schools:*
According to the teaching of absolute Buddha nature [Madhyamika], all beings have Buddha nature. According to the teaching of developmental nature [Yogacara], things happen in dependence on conditions, so sentient beings may more may not have Buddha nature. (pg. 215)
This seemingly different view between the Buddhist Madhyamika school of philosophy and the Buddhist Yogacara school sounds like a contradiction, but Master Yin-Shun says that it’s not. It’s just two sides of the same coin. Regarding the Madhyamika view:
Absolute Buddha nature means that all things are fundamentally without an independent nature of their own; that is, their fundamental nature is empty and still…Fortunately, all things are empty and without an independent nature, so defilements can become pure, confusion can become enlightenment, and the common can be holy. Therefore it is said, ‘Because existence is empty, all things can be formed.’ (pg. 214)
The Yogacara view is as follows:
Scholars of the Mere Conscious system [Yogacara] say that relying on ‘the hearing and practicing of the universal outflow of the Dharma realm (the Buddha’s teachings),’ one has the potential to become a buddha. The Lotus Sutra’s passage ‘Buddha-seeds arise from conditions’ is based on the teaching of the developmental nature. (pg. 215)
Master Yin-Shun then brings it together:
The empty nature of all things [Madhyamika] serves as the principle for the possibility of sentient beings to become buddhas. Reliance on the buddhas’ and bodhisattvas’ teachings and resolution to learn and practice serves as the nature through which beings develop into buddhas. (pg. 215)
So Buddha nature isn’t something inherent, nor is it anything like a soul or consciousness or anything. As stated above, all things are empty of a permanent, or independent nature. Everything arises from previous causes and conditions, and everything is subject to change. This is good as it means that one can change from an ordinary being into a buddha. In order to trigger that change, one listens to the Buddha’s teachings, and awaken a desire for Enlightenment.
On the subject of Enlightenment, or bodhi, Master Yin-Shun goes into more detail:
Once the resolve to attain bodhi [enlightenment] has arisen, it will always be the cause and condition for one to become a buddha and will not be lost — this is described in the Lotus Sutra’s analogy of the pearl that has been tied on.** But this resolve cannot be said to be originally possessed; it is formed from making the resolution and from being influenced by the universal teaching of the Buddha. When one has the bodhi-mind seed, one relies on this Buddha nature to practice gradually. Gradual practice causes the pure function of the Buddha-seed to grow from the bottom grade to the middle and then to the top…After much practicing, one brings forth faultless and pure virtues. (pg. 216)
So that’s an indepth look at Buddha-nature in Buddhism.
P.S. It should be noted that Master Yin-Shun belongs to the Chinese San-Lun (三論) school of Buddhism, which is rooted in Madhyamika philosophy. However, Master Yin-Shun is well known for his breadth of knowledge of Buddhist texts and seems to manage to go beyond doctrine to get to the root of things. His writings are quite good, I think. :D
* – If I recall right, Theravada Buddhism’s philosophy falls under a third category of Abhidhamma philosophy, but I know little about it. Reading the Abidhamma itself can be excruciating in detail, I have heard. Still, I’d love to tackle it one day.
** – Master Yin-Shun also points out that analogy of wisdom as a pearl appear is such sutras as the Sutra of the Ten Stages and the Sutra of the Great Assembly. This inspired me to write Wikipedia articles on both sutras (since they’re important to East Asia, but largely unknown here). ;)
The articles are short, but trying to figure out what the Chinese and Pinyin were took up most of an evening. Beats video games I guess. ;p