Bridging Eastern and Western Logic and Philosophy

Nāgārjuna’s Tetralemma in Yamauchi Tokuryū’s Philosophy

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Yamauchi Tokuryū (1890-1982) was a prominent Japanese philosopher known for his efforts to bridge Eastern and Western philosophical traditions. His philosophical work is particularly noted for its synthesis of Nāgārjuna’s tetralemma with Western logic, creating a unique approach to understanding complex philosophical problems such as causation. 

This overview aims to provide an accessible explanation of Yamauchi’s philosophy, focusing on his interpretation of Nāgārjuna’s tetralemma (catuṣkoṭi in Sanskrit) and on the way he used the Buddhist concept of dependent co-arising (pratītyasamutpāda in Sanskrit).

Yamauchi Tokuryū’s Life and Work

Yamauchi Tokuryū 山内得立, originally named Nakagawa Tokuryū 中川得立, was born on June 12, 1890, in Tenma Village, Nara Prefecture, Japan. He pursued philosophy at Kyoto Imperial University, graduating in 1914. In 1918, he married Yamauchi Masako and took her surname, inheriting her father’s fortune. Sadly, she passed away in 1919.

Yamauchi then traveled to Europe to further his studies, attending lectures by notable philosophers like Edmund Husserl and Martin Heidegger at the University of Freiburg. Upon his return to Japan in 1923, he joined Tōkyō Shōka University (now called Hitotsubashi University) as a lecturer and later became a professor. He married a second time in 1926 to Gamō Ei, who saw her husband receive his PhD in 1930 under the supervision of Nishida Kitarō before she died in 1931. In 1932, he married again to Takeda Mieko.

Yamauchi held various academic positions, culminating in his 1946 appointment to the First Chair of Philosophy and History of Philosophy — a position similar to a dean — at Kyoto University, a post previously held by eminent philosophers such as Nishida Kitarō or Tanabe Hajime.

He served in this position until 1953 and continued his academic career at other institutions, such as Ryukoku University, where he taught until 1980. 

Yamauchi was a prolific writer who made in his country significant contributions to the fields of Greek, medieval, and modern European philosophy, as well as Eastern philosophies. He died on September 19, 1982, at the age of ninety-two. 

He was deeply influenced by a wide range of philosophical traditions. His studies included ancient Greek philosophy, European medieval philosophy, German idealism, phenomenology, and existentialism. His goal was to create a dialogue between Eastern and Western thought, seeking a synthesis that could address the philosophical limitations of both traditions.

Yamauchi’s major work, Logos and Lemma 『ロゴスとレンマ』 (1974), exemplifies his integrative approach. In this work, he explores how different philosophical systems, including Buddhist ones, can be reconciled to form a more comprehensive understanding of reality — or at least of some parts of reality. 

Bridging Eastern and Western Thought

Yamauchi explains his significant effort to integrate Eastern and Western philosophical traditions as follows:

The development of logos [i.e. Western logic] culminated with Hegel, but to say that there is no logic outside of logos constitutes an excess of authority — even the arrogance — of Western thought. In the East, there is also a logic. It is the logic of the lemma. By presenting it and explaining what is, by contrast with the West, the characteristic of Eastern thought, in a certain sense we want to strongly establish a system of thought for the whole world. The logic of the lemma is not just an Idealtypus of Eastern culture; it supports one of the wings of a global system of thought, and I even think that the act of distinguishing each of these [wings], while simultaneously embracing both of them, could constitute the achievement of a global system of thought. This book is nothing else than such an attempt. (Yamauchi 1974: 67)

According to him, Western philosophy’s emphasis on rigorous logical analysis can be enriched by Eastern philosophy’s less dualistic perspectives. By synthesizing these approaches, he aimed to create a more global and inclusive system of thought. His use of the tetralemma is a core element of this integrative effort, offering a way to move beyond the limitations of dualistic logic to a more nuanced view of reality.

It is important to remember that Yamauchi attempted to build this bridge after the Second World War. The political significance of his attempt is clear, if not always explicit. In the context of the possibility of humanity’s self-annihilation, the need for intercultural and philosophical rapprochement has reached a new level of urgency.

It is in this humanistic pursuit that he used the tetralemma, a famous logical way of thinking.

Understanding the Tetralemma

The tetralemma (catuṣkoṭi in Sanskrit, meaning for propositions) is a logical framework developed by Nāgārjuna, a foundational figure in Mahāyāna Buddhism. Nāgārjuna’s tetralemma consists of four possible logical alternatives to any statement or proposition:

1. It is true / affirmation.

2. It is not true / negation

3. It is both true and not true / biaffirmation.

4. It is neither true nor not true / binegation.

This framework is used by Buddhists to deconstruct conventional views and expose the limitations of common ways of thinking. By presenting these four possibilities, Nāgārjuna encourages a deeper exploration of reality. It ultimately leads to a simple insight: there is a gap between what we think about a thing and the thing itself. In other words, one thing is certain: our knowledge is a construction and not reality itself.

Yamauchi’s Interpretation of the Tetralemma

Yamauchi Tokuryū reformulated Nāgārjuna’s tetralemma by integrating Western logical principles in order to overcome the limitations of dualistic logical thinking prevalent in Western philosophy.

Indeed, traditional Western logic, rooted in Aristotelian principles, typically operates within a binary framework of true or false, of affirmation or negation — following the law of identity, the law of non-contradiction, and the law of the excluded middle. 

Yamauchi realized that such dichotomous thinking was insufficient to capture the complexity of some objects of knowledge as well as some processes that occur in reality.

By reformulating the tetralemma’s fourfold logical structure, which includes the possibilities that a statement is true, not true, both, or neither, Yamauchi provided a more flexible, nuanced, and perhaps more consistent approach to understanding our world. The four new propositions he introduced are

1. It is true / affirmation.

2. It is not true / negation.

3. It is neither true nor not true / binegation.

4. It is both true and not true / biaffirmation.

Yamauchi’s innovative synthesis of the tetralemma and Aristotelian principles aimed to create a comprehensive philosophical system capable of addressing the intricate and interconnected aspects of reality, thus promoting a more comprehensive perspective. 

In what sense is it a synthesis?

It is a synthesis in the sense that the first two lemmas (affirmation and negation) respect Aristotelian logic and implicitly recognize it as efficient with respect to some objects of knowledge, while the last two lemmas (binegation and biaffirmation) are open to a broader, though less precise, understanding of objects that cannot be properly grasped in any other way.

In particular, this reformulation allowed him to explore the connection between cause and effect; emphasizing their interdependence. In the language of the tetralemma, starting from the idea that cause and effect are neither dependent nor independent (binegation), Yamauchi proposes that they are both dependent and independent of each other (biaffirmation). 

This allows him to avoid the need for cause and effect to be completely independent of each other and only relative to each other. It is also a way of saying that not only does the effect result from the cause, but the cause itself is to some extent — but only to some extent — dependent on the effect being a cause.

This approach is consistent with his use of the Buddhist concept of “dependent co-arising” (pratītyasamutpāda), which holds that all phenomena arise in dependence upon a web of interrelated conditions, rather than in isolation.

The Concept of Dependent Co-Arising

Dependent co-arising (pratītyasamutpāda) is a core concept of Buddhist philosophy with a long history. It embraces various interpretations and meanings. In the way that Yamauchi used it, it emphasizes the interconnectedness of all things. 

According to this idea, nothing exists independently; instead, everything depends on a complex network of causes and conditions. This concept famously questions the notion of inherent, independent existence and emphasizes the interdependent nature of the constituents of what we know as reality.

Drawing a more or less clear equivalent between the fourth lemma (biaffirmation) and dependent co-arising, Yamauchi used the tetralemma to explore the implications of dependent co-arising for philosophical discussions of causation. 

He believed that by recognizing that the relationship between cause and effect is interdependent, but not always necessary, philosophers could develop a more comprehensive and flexible approach to understanding the world. In particular, Yamauchi sees his own views as the basis of nothing less than free will.

The Husband-Wife and Child-Parents Relationships

Yamauchi’s philosophy is both logical and metaphysical. It is not always easy to understand what kind of concrete phenomenon can be grasped from to his views. However, he does provide very few examples to illustrate his thinking. 

He gives, for instance, the example of husbands and wives (fūfu 夫婦). The situation is simple: let’s take a woman and a man; they do not know each other, and they are independent. Eventually, they meet each other and enter a “husband and wife” relationship; the man becomes the woman’s husband, and the woman becomes the man’s wife. 

They do not become husband and wife by the will of some gods, but by their own free will, which takes place in a specific context with which they are interdependent: it is not then a complete state of freedom.

A second example given by Yamauchi is the relationship between a child and its parents. Biologically speaking, a “natural” child is a child born of two parents. But before a child is born, the parents are not parents, and before the child is born, the child does not exist. 

Then, from a biological point of view, a child is always someone’s child, even if its parents can’t raise it or are dead. However, parents are not always parents: if their child dies and they don’t have another child, they can no longer be considered parents.

Yamauchi is particularly clear on this point. This suggests that, for him, both the qualities and the relationships described by the concept of dependent co-arising are not only metaphysical, but also concrete specifics and connections. They may have different connotations depending on the culture and people involved.

Conclusion

Yamauchi Tokuryū’s creative integration of Nāgārjuna’s tetralemma with Western logic offers an interesting logical framework to understanding reality in its complexity. By bridging Eastern and Western philosophical traditions, his work provides insights into the interconnected and interdependent nature of beings.

His philosophy encourages a more nuanced and inclusive view of the world, emphasizing the importance of integrating different perspectives to address the complexities of our reality.

By exploring the rich interplay between Eastern and Western thought, Yamauchi’s work has recently begun to inspire and inform contemporary philosophical discussions, and could usefully be compared to the work of logicians such as Graham Priest.

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To know more about Yamauchi’s philosophy, one can read my book published in French in 2023 and entitled Yamauchi Tokuryū (1890–1982). Western Philosophy and Buddhist Thought.

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Romaric