This article discusses the use of Bayes’ Theorem in medical diagnosis with a view to examining the epistemological problems of interpreting the concept of pre-test probability value. It is generally maintained that pre-test probability values are determined subjectively. Accordingly, this paper investigates three main philosophical interpretations of probability (the “classic” one, based on the principle of non-sufficient reason, the frequentist one, and the personalistic one). This study argues that using Bayes’ Theorem in medical diagnosis does not require accepting the radical personalistic interpretation. It will be shown that what distinguishes radical and moderate personalist interpretations is the criterion of conditional inter-subjectivity which applies only to the moderate account of personalist interpretation.

本文讨论贝叶斯定理在医学诊断中的应用，以探讨解释预测概率值概念的认识论问题。通常认为预测试概率值是主观确定的。因此，本文研究了概率的三种主要哲学解释（基于非充分理由原则的“经典”解释、频率论解释和个人主义解释）。这项研究认为，在医学诊断中使用贝叶斯定理不需要接受激进的个人主义解释。我们将表明，区分激进个人主义解释和温和个人主义解释的是有条件的主体间性标准，该标准仅适用于个人主义解释的温和解释。