 Okasha makes an important point about the intransitivity of covariance that is relevant to Lewontin’s principles. Okasha writes that Lewontin’s last two conditions essentially require covariance between offspring number and parental character (Principle 2), along with covariance between parental character and offspring character (Principle 3). (Here, Okasha is interpreting “fitness” in Lewontin’s conditions as offspring number rather than as a variable in a formalism quantifying selection in its focused sense.) Both those last two covariances might be positive without the system exhibiting an evolutionary response (as would occur if some of the parents with a given character have especially many offspring that do not especially resemble them, while other parents with the same character have offspring that especially resemble them but do not have especially many of them). For a system to exhibit an evolutionary response, Okasha requires that the covariance between parental offspring number and average offspring character be positive (2006: 37).