  Preferences often change -- even in short time intervals -- due to either the
mere passage of time (present-biased preferences) or changes in environmental
conditions (state-dependent preferences). On the basis of the empirical
findings in the context of state-dependent preferences, we critically discuss
the Aristotelian view of unitary decision makers in economics and urge a more
Heraclitean perspective on human decision-making. We illustrate that the
conceptualization of preferences as present-biased or state-dependent has very
different normative implications under the Aristotelian view, although both
concepts are empirically hard to distinguish. This is highly problematic, as it
renders almost any paternalistic intervention justifiable.
