Philosophy lacks criteria to evaluate its philosophical theories. To fill this gap, we introduce nine criteria to compare worldviews, classified in three broad categories: objective criteria (objective consistency, scientificity, scope) subjective criteria (subjective consistency, personal utility, emotionality) and intersubjective criteria (intersubjective consistency, collective utility, narrativity). We first define what a worldview is and expose the heuristic used in our quest for criteria. After describing each criterion individually, we show what happens when each of them is violated. From the criteria, we derive assessment tests to compare and improve different worldviews. These include the is-ought, ought-act and is-act first-order tests; the critical and dialectical second-order tests; the mixed-questions and firstsecond-order synthetical third order tests; and the we-I, we-it and it-I tests. Then we apply these criteria and tests to a concrete example, comparing the Flying Spaghetti Monster deity with Intelligent Design. As another application, we draw more general fruitful suggestions for the science-and-religion dialog.