Knowledge and Decision

• Applicant: Professor Dr. Moritz Schulz
• Subject Area: Theoretical Philosophy
• Term: from 2016 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 315078566

The proposed project 'Knowledge and Decision' is located at the interface of epistemology and decision theory. Its ultimate goal is to devise an integrated theory of theoretical and practical rationality. Epistemologically, it takes up the recent trend to reassign the concept of knowledge a fundamental role. The decision-theoretic implications of this approach are still under-explored. On the other hand, there is currently a renewed interest in decision theory. This provides great research opportunities for exploiting the feedback loops running both ways between epistemology and decision theory. More specifically, the project is structured into eight subprojects concerned with: knowledge, uncertainty, belief, desire (preferences), representation, causation, language and rationality. 1) It is a widely held thought, going back to Plato's Meno, that the value of knowledge is to make for better decisions. Although more informed decisions can in general be expected to be better, it is as yet unknown whether knowledge as opposed to mere true belief is decision-theoretically advantageous. 2) Despite its comeback in epistemology, the concept of knowledge is absent from standard (Bayesian) decision theory. If the human search for knowledge is largely driven by an interest in better decisions, one should have expected the reverse. A major obstacle for integrating knowledge into decision theory is that it does not seem to square well with decision-theoretic theories of uncertainty. 3) Another important aspect is that decision theory is standardly cast in terms of more subjective, belief-like attitudes, which seem to be more immediately accessible to an agent. The project will therefore explore the relation between knowledge and belief more closely, following-up on the idea that knowledge is the aim of belief. 4) Quite generally, decisions can be seen as the joint product of our knowledge about the world and our desires or preferences. Yet these two components do not seem to be completely independent, for the preferences of an agent can be influenced by what the agent believes to be good for her. Recent research on a structurally similar problem in the debate about conditionals promises to be fruitfully applied to this issue. 5) Further, belief and desire have content, which can rationally change over time under the impression of new information. Recently, it has become a major question how to describe the joint dynamics of belief and desire. 6) Beliefs in decision-making typically concern the possible consequences of the options available to the agent. However, the question whether the pertinent notion of consequence is to be understood causally or evidentially has to be revisited in the light of recent research. 7) A study of the language of decision promises a more realistic picture of actual decision-making. 8) Ultimately, the project aims at a unified theory of rationality which lets knowledge play a fundamental role.

• DFG Programme: Independent Junior Research Groups