The Four Noble Truths often stand out as the central ideas of Buddhism among Western Buddhists and perhaps rightly so. The recognition of the fact of suffering, the cause of suffering, the elimination of suffering, and the practical method for doing so is critical to any understanding of Buddhism. All schools of Buddhism accept these truths. After the Four Noble Truths, the concept of the bodhisattva is perhaps the second most significant Buddhist concept. It is among the advances over primitive Buddhism that the Mahayana school generated. Embracing these ideas is likely to place one squarely on the path of the Buddha, refine one's spirituality, and enhance the quality of one's life. The history of Buddhism, however, offers more subtle concepts than these which can lead one still deeper into the enlightenment that Buddhism offers. Chief among these, according to T.R.V. Murti, is the concept of sunyata, or what some have translated as "emptiness," which he admirably explicates in his masterful work, The Central Philosophy of Buddhism.
The work is divided into three parts: the origin and development of the Madhyamaka philosophy, an exposition of the philosophy itself, and a comparison of it to other systems, especially Western philosophical systems. This is not a book for beginners. To appreciate the work, one should already have a good background in the Madhyamaka tradition, but also the Theravada, Sarvastivada, and Yogacara Buddhist traditions and the Hindu Advaita Vedanta.
The "central philosophy" that Murti identifies is a philosophical "dialectic" advanced by the Buddhist philosopher Nagarjuna which results in the recognition that absolute reality is sunyata or emptiness. The Madhyamika first of all accepts that there is a division between the world of ordinary experience and absolute reality. This sets it apart from the early Buddhism of the Theravada and Sarvastivada schools, which asserted the reality of the dharmas, i.e., elemental or atomic units of existence which were infinitesimally extended in time and space. Early Buddhism rejected the ultimate reality of composite objects, including the self. Indeed, on this view all things lack substance or permanent identical reality. Consequently, early Buddhism did not maintain an absolutist metaphysic.
In contrast, the Madhyamaka view accepts that there is an absolute reality beyond the ordinary empirical realm composed of the early Buddhist dharmas, but it rejects any suggestion that our reason can bring us to understand this reality. This sets Madhyamaka Buddhism apart from two other absolutist philosophies, the Yogacara's Vijnanavada or Consciousness Only philosophy, and the Upanishadic Advaita Vedanta philosophy which posits the absolute as Brahman and equates it with Atman, making the absolute a kind of universal soul.
According to Murti, all three of these non-Madhyamaka philosophies are speculative metaphysics which the Madhyamaka school rejected through its dialectical critique. Madhyamaka Buddhsim exposed contradictions within each of systems and furthermore claimed that any metaphysical doctrine would fall apart under similar careful examination. However, instead of becoming nihilistic, the Madhyamaka philosophers merely concluded that reason was simply incapable of grasping the absolute and that instead, it must be immediately intuited in a non-discursive way.
One of the most informative observations in Murti's work is his comparison of the Madhyamaka philosophy to the critical philosophy of Immanuel Kant. The contradictions uncovered in the Madhyamaka dialectic function much in the way the Kant's antinomies function in the Critique of Pure Reason. For Kant, the antinomies show that reason cannot reveal the true nature of the noumenal world (the absolute). Instead, we can merely know that our understanding of the world is shaped by the nature of our reason -- by the forms of intuition and the categories of understanding that are the standard operating equipment for how we construct the empirical world. According to Murti, the Madhyamika and Kant differ in that "Kant's Transcendental dialectic is directed against speculative metaphysics...not because he did not believe in the reality of God, Freedom and Immortality of the Soul, but because he wanted to make them safe from the unwarranted ascriptions of pure Reason. The difference between the two...is that Kant seeks to realise these noumenal realities in a non-intellectual mode -- Faith and practical Reason; the Madhyamika does it in Intellectual Intuition -- Prajnaparamita."
As profound as Murti's work is, I am left wondering whether the dialectic of the Madhyamaka philosophy, insofar as it is based on The Large Sutra of Perfect Wisdom, is not more like Kant's critical philosophy than he suggests. Where Kant resorts to practical reason to arrive at his absolute (the three transcendental ideas: God, freedom, and the immortal soul), The Large Sutra of Perfect Wisdom employs "skill in means" to perfect wisdom and reach the "Intellectual Intuition" of the absolute. Skill in means seems nothing if not practical reason unconsciously performed.
Regardless of this criticism, Murti's work is among the finest treatments of Buddhist epistemology and metaphysics ever written. Anyone seeking a good understanding of Buddhism would be well-advised to procure a copy and, while reading it, search out whatever other works might fill in the gaps of one's understanding.