The Madhyamaka school, founded by the Buddhist philosopher Nagarjuna, is one of the most influential schools of Mahayana Buddhism. It is based on the teachings of the Prajnaparamita sutras, which emphasize the concept of emptiness (shunyata) as the ultimate nature of reality. The Madhyamaka school is also known as the "Middle Way" school, as it seeks to find a middle ground between the extremes of eternalism and nihilism.

The main principles of the Madhyamaka school can be summarized as follows:

1. Emptiness: The concept of emptiness is at the core of Madhyamaka philosophy. It states that all phenomena, including ourselves, are ultimately empty of inherent existence. This means that nothing has a fixed, independent, or permanent nature. Everything is dependent on causes and conditions, and therefore, lacks inherent existence.

2. Two Truths: The Madhyamaka school distinguishes between two levels of truth - conventional truth and ultimate truth. Conventional truth refers to the everyday, relative reality that we experience, while ultimate truth refers to the ultimate nature of reality, which is emptiness. According to Madhyamaka, these two truths are not contradictory but complementary.

3. Dependent Origination: This principle states that all phenomena arise in dependence on causes and conditions. Nothing exists independently or by itself. This concept is closely related to the concept of emptiness, as it emphasizes the interdependent and impermanent nature of all things.

4. Non-Duality: The Madhyamaka school rejects the dualistic view of reality, which sees things as either existing or not existing. Instead, it emphasizes the non-dual nature of reality, where things are neither existent nor non-existent. This is because all phenomena are empty of inherent existence and therefore cannot be categorized as either existing or non-existing.

5. Middle Way: The Madhyamaka school advocates for the Middle Way, which is the path between the extremes of eternalism and nihilism. Eternalism is the belief in a permanent, unchanging self or reality, while nihilism is the belief in the non-existence of self or reality. The Middle Way recognizes the conventional reality of things while also understanding their ultimate nature of emptiness.

Overall, the Madhyamaka school teaches that the ultimate nature of reality is emptiness, and understanding this can lead to the cessation of suffering. It emphasizes the importance of seeing things as they are, without grasping onto fixed concepts or ideas. By following the Middle Way and understanding the two truths, one can attain enlightenment and achieve liberation from suffering.