 Two kinds of beliefs are especially important for doxastic models. The first is the belief that the presence of state \(X\) makes a desired state \(Y\) more likely. Take for example the belief that fluoride prevents dental cavities. This can lead a person to prefer fluoride toothpaste to others. If she comes to disbelieve this connection, she may well abandon this preference. More generally, if \(X\wedge Y\) is preferred to \(X\wedge \neg Y\), then a rise of the probability that \(Y\) given \(X\) will result in a rise in the desirability of \(X\), and vice versa.