Risk and uncertainty are inherent in the environment and functions of accounting. Accounting reports, systems, norms, and rules help people decide, and also determine how they decide in such environment. Diverse normative theories and descriptions of coping with risk and uncertainty yield different implications for accounting. Chambers was an articulate, forceful, and celebrated proponent of market values, while Ijiri did the same for historical costs. Elements of accounting theory that diverge in their emphases on historical cost versus market values can be linked to the divergence in the theories of risk and decision making. This largely unrecognized link between the conflicting accounting theories and their respective implicit assumptions about risky decisions may help us reconcile, understand and progress beyond the accounting debates of the past century.