Caterina Sisti PhD

March 1st until August 31st, 2021

Affiliation: Department of Philosophy Scuola Normale Superiore Pisa, Italy

Research for a study about:

On Laws and Conditionals from Cambridge to Vienna – an Investigation of the Similarities between the Accounts of lawlike Generalizations and Conditionals of  Ramsey and Hempel

Abstract of the research project:

During his short life, Ramsey traveled several times to Vienna and he had contacts and exchanges with some of the members of the Vienna Circle. In 1927 Ramsey invited Schlick to give a paper to the Moral Science Club and in 1929 he wrote to him about his intention to review Carnap's Der logische Aufbau der Welt. In Vienna, Ramsey was well known for his contribution to the debate on the foundation of mathematics with his 1925 paper. He was considered a scholar related to the Circle and listed in its manifesto in 1929. While Ramsey's contribution to philosophy of mathematics was acknowledged in Vienna during his life, Ramsey's work on scientific theories was discovered only later.
In the 1950s Hempel appreciated Ramsey's Theories and in his 1958 paper, The Theoretician's Dilemma: a Study in the Logic of Theory Construction, Hempel introduced the Ramsey sentence.
The aim of this project was to investigate what influence Ramsey's work had on Hempel's. I was particularly interested in their accounts of  generalizations and conditional sentences, and how the latter are related to the former.


Ramsey's account of conditionals and proposing a contemporary development of his approach.

Date:  April 22, 2021

Time: 3–5pm (CET)

Online Plattform: Zoom| for the APSE-IVC talk series

During my stay in Vienna, two other talks on the same topic were given at the ICT Paris and at the “Scientific Models and Scientific Inference” workshop in Varese


During the six months spent at the Institute Vienna Circle, the study of Hempel's view of laws and generalizations in his works from the 1950s to the 1960s has shown many similarities with Ramsey's late account of generalizations. Furthermore, for both, conditionals, and especially counterfactuals, have a peculiar relation with laws and generalizations.
In the latest years of his life, Ramsey abandoned logicism in favor of finitism in mathematics. This is particularly evident in his 1929 paper General Propositions and Causality, where he puts forth a non-propositional account of generalizations: “all men are mortal” is no longer read as an infinite conjunction but as a rule for judging “if x is a man then x is mortal”.  According to Ramsey, generalizations can be of two types: laws and chances. The latter are probabilistic generalizations. Counterfactuals are instances of generalizations, together with additional implicit information, usually indicated by the context. Thus, the antecedent of the conditional with the additional information imply the consequent after a generalization.
Hempel's distinction between laws and statistical generalizations in Deductive-Nomological vs. Statistical Explanation  resembles Ramsey's categorizations of laws and chances. The systematization of the arguments with the two premises and the conclusion can be read as a Ramsey's counterfactual. The first premise is the generalization of which the conditional is an instance, the second premise is the antecedent of the conditional together with the additional implicit information, and the conclusion of the argument is the consequent. In fact, Hempel suggests that statistical and nomic generalizations are strictly related to counterfactuals. However, there are two main differences between the two accounts: first, for Hempel laws are propositions, but not for Ramsey. Second, Hempel believes that the logic of statistical arguments totally differs from that of nomological ones. This is not the case for Ramsey, who argues, in Truth and Probability, that probability can be seen as a “generalization” of deductive logic, where arguments obey the same consistency constraint.