Paper short abstract:

As Chinese horoscopy aims at giving an accurate - though not legal - diagnosis of a complex and multi-dimensional reality, I propose to show how contemporary diviners in Taiwan have developed a rational method which can serve as a model of judging and decision-making under uncertainty.

Paper long abstract:

As Chinese horoscopy aims at giving an accurate - though not legal - diagnosis of a complex and multi-dimensional reality, I propose to show how contemporary diviners in Taiwan have developed a rational method which can serve as a model of judging and decision-making under uncertainty.

Diviners are torn between the need to be efficient (predict something somehow) and the risk to go beyond their competence (make a wrong prediction). To cast the doubts of petitioners who often put to test their efficacy and to distinguish themselves from charlatans who pretend they can predict anything, Taiwanese horoscopists of the "modern trend" are careful to make a fair use of their authority and advocate a scientific method whose scope is precisely defined and limited.

They rely on a rigorous formal pattern which combines theoretical concepts (such as fate), technical device (such as horoscope's grid) and contradictory oral exchange (during the consultation) to investigate the situation of a particular person in interaction with a particular environment. As judges would do, diviners use every type of proof (oral, material, sociological, psychological) to reconstitute the bundle of factors which determines a human being at a particular time. When assessing the situation, they also make a clear distinction between elements which depend on the free will of the individual and those which are beyond his control. As experts, diviners go rationally through every component of the case but also rely on their own experience as human beings to build their opinion and convince the petitioner.