The Formal, Normative Theories of Savage, De Finetti, and Savage and De Finetti Require Additivity. They Never Introduced Sub or Non Additivity (Interval Valued Probability, Imprecise Probability, Indeterminate Probability) into Their Formal, Normative Theories of Subjective Probability or of Maximizing Subjective Expected Utility
Preprint in SSRN Electronic Journal (January 2017)