To promote interdisciplinary interaction between different faculty members and students on the campus, a weekly meeting has been organized by our postdoc Jialiang Yan since September 2023, called Tsing Ch’a Sessions (清茶会). Its slogan “know thyself and let others know you better.”
■Schedule for 2025-2026 academic year (Autumn)
| Date | Speaker |
|---|---|
| 2025 Nov 6 | Qian Chen 陈谦 (Tsinghua University) |
| 2025 Dec 11 | Weijun Yu 余伟俊 (Tsinghua University) |
| TBA | Wenlong Zheng 郑文龙 (Tsinghua University) |
| TBA | Yumin Ji 池幽旻 (Tsinghua University) |
| TBA | Xin Li 李鑫 (Tsinghua University) |
| TBA | Mingjia Zuo 左明家 (Tsinghua University) |
| TBA | Mingjun Chen 陈铭骏 (Tsinghua University) |
| TBA | Zhizhen Ma 马郅真 (Tsinghua University) |
■Current Sessions
2025 Dec 11 15:00-16:30 Weijun Yu (余伟俊, Tsinghua University) From Seeing-as to Knowing-as: On Mohist Knowledge and Logic
In his Philosophical Investigations, Wittgenstein distinguishes between seeing and seeing-as, arguing that in seeing we do not merely receive perceptual input but interpret the object under different aspects. Inspired by this distinction, Michael Beaney develops the notion of knowing-as, which differs from knowing-that and knowing-how, concerning the aspects in which something is known. Knowing-as is structurally ambiguous: the expression “I know X as Y” may mean “I know X-as-Y,” or “I-as-Y know X.” These two structures correspond respectively to aspectual knowledge and perspectival knowledge. In this talk, I will focus on Mohist epistemology and logic to analyze the concept of knowing-as. First, I will review Wittgenstein’s distinction of seeing/seeing-as and Beaney’s theory of knowing-as, comparing with the parallel analogy of seeing and knowing in Mohist Canon, to establish a bridge between seeing-as and knowing-as. Second, I will discuss the two senses of knowing-as in Mohist philosophy: I will relate knowing-as to Mohist concept leiqu類取(‘selecting according to kind’) and compare Mohist and Zhuangzian perspectival epistemology. Finally, since knowing-as is also closely connected to analogical reasoning, which is seen as the central feature of Chinese logic, I will quote Beaney’s logical interpretations of the Happy Fish Dialogue and argue that Mohists have a theory of analogical justification.
2025 Nov 6 16:00-17:30 Qian Chen (陈谦, Tsinghua University) Degree of Kripke-incompleteness of tense logics
Tense logics are normal bi-modal logics with ‘future-looking’ and ‘past-looking’ modalities. The degree of Kripke-incompleteness of a logic L in some lattice C of logics is the cardinality of logics in C which share the same class of Kripke-frames with L. A celebrated result on Kripke-incompleteness is Blok’s dichotomy theorem for the degree of Kripke-incompleteness in the lattice NExt(K) of all normal modal logics: every normal modal logic L is of the degree of Kripke-incompleteness 1 or continuum. In this talk, we focus on the lattice NExt(K4t) of all normal extensions of K4t, where K4t is the tense logic of transitive frames. We show that Blok’s theorem of the degree of Kripke-incompleteness for modal logic K can be extended to K4t.
■Past Sessions
Click HERE to check the past sessions.
