Buddhists regard life as a wheel, cycling through death, birth and rebirth.
Buddhists regard life as a wheel, cycling through death, birth and rebirth.

The founding documents of Buddhism in all its forms are the Tripitaka, or "Three Baskets", compiled in the first century B.C. All subsequent Buddhist belief flows from the core teachings of Gautama Buddha as recorded in the Tripitaka. Today three major branches of Buddhism exist, with a plethora of tributary sects, but the basic structure of belief is roughly the same throughout the world. Most Buddhist thought is aimed towards a single goal -- achieving nirvana, or liberation from the cycle of life and death.

The Wheel

A core concept of Buddhist belief is the wheel, which symbolizes that life is a continuous cycle of birth, life, death, and rebirth, or reincarnation. The cycle can be understood in terms of physical beings being born, living, dying and being reborn, or in a more metaphorical sense, the ups and downs of a single lifetime. In psychological terms, the rise and fall of joy, pain, and other emotions is seen as a manifestation of the wheel.

Karma

Karma is the idea that our actions have consequences for us or others in the future, whether in this life or in the next incarnation. These actions can be positive or negative, moral or immoral, and thus many Buddhists hold that karma can have a beneficial, detrimental, or neutral effect on the pursuit of nirvana. The Four Noble Truths and the Eightfold Path provide the basic instructions for maximizing good karma, minimizing the bad, and thus eventually achieving liberation.

Non-Self

The ancient Vedic society from which Buddhism emerged understood the self or ego as eternal and unchanging -- the true essence of the non-physical body. But Gautama Buddha believed that nothing was permanent, and change was the only constant. Therefore, according to the Vedic definition of self, the Buddha concluded that the self could not exist. Buddhism has since then been strongly centered around the idea that there is no such thing as the self. The consequences of this one precept are multitudinous, and informs the entirety of the religion's canon.

The Four Noble Truths

All Buddhist traditions take the Four Noble Truths as a starting point from which all other thought flows. Those truths are that existence is suffering, caused by grasping and rejecting, therefore one can end the suffering by refraining from doing either. The Eightfold Path guides Buddhists towards this liberation through a non-sequential, concurrent set of principles.

The Eightfold Path

The Eightfold Path is not a linear eight-step program, but a set of concepts designed to teach the impermanence and interconnectedness of all things and ultimately to guide the practitioner towards nirvana. Those concepts are: right knowledge, or the rational pursuit of the truth; right intention, which implies aspiring to behave morally; right speech, which involves speaking kindly and telling the truth; right action, such as refraining from harming living things or stealing; right livelihood, by choosing a vocation that harms no one; right effort, towards a clear mental state; right mindfulness, or active awareness; and right concentration, which is the culmination of the other seven principles.

The Bodhisattva

The "bodhisattva" figures prominently in all Buddhist traditions. Theravada and Mahayana traditions define the bodhisattva as one who actively seeks enlightenment. Other traditions -- such as Chinese Buddhism -- teach that one can choose to become a bodhisattva instead of attaining nirvana. The bodhisattva sacrifices enlightenment to show other people how to attain it -- even if it takes an infinite number of cycles of birth and death to accomplish the task. The difference between the two definitions is subtle, but important to Buddhists.