To assess the effect of the two Reagan administrations on conservatism, several cautionary notes must be observed. For one thing, no one can predict with any certainty what the effect of the Reagan years will be. As Edmund Burke once said, the future isn't determined by the past. Second, no president ever accomplishes everything he sets out to do. President Reagan aimed to reverse a half-century of history; that ambitious program could not possibly be completely successful. Third, the Reagan administrations do not have coherence. Several initiatives are compatible with long-standing conservative themes, while others continue reflexive New Deal ideas--for example, Social Security benefits. Fourth, the full effect of the Reagan years won't be known for some time. Presumably, President Reagan planted ideas that will flourish under another president's care or will die in the ground, unwatered by an administration with a different agenda. Fifth, some of President Reagan's unacted-upon suggestions may have longer-term benefits than ideas put into motion. For example, the elimination of the corporate income tax, which translates into double taxation on dividends and discourages investment, and the deployment of some forms of the Strategic Defense Initiative immediately come to mind.