 The normative implications of anthropological reflection about life and history also led Dilthey to address the value of worldviews. Just as the nature of universal history forces us to conceive of history as more than a human science, so worldviews are more broadly based attempts at acquiring a unified perspective on life. The sciences are by their nature partial and cannot provide a comprehensive worldview. A worldview attempts to provide not only a cognitive picture of the world, but also an estimation of what in life is valuable and worth preserving, and finally how we can strive to improve reality. Worldviews have been developed in literary, religious and philosophical works. Philosophers have produced metaphysical formulations of worldviews that attempt to give them a universal conceptual determinacy. Dilthey analyzes three recurrent types of such metaphysical formulations: naturalism, the idealism of freedom, and objective idealism. The naturalism of Democritus, Hobbes and others derives everything from what can be cognized and is pluralistic in structure; idealism of freedom as found in Plato, Kant, and others insists on the sovereignty of the will and is dualistic; objective idealism as found in Heraclitus, Leibniz and Hegel affirms reality as the embodiment of a harmonious set of values and can be considered monistic. The three types of metaphysical worldviews are incommensurable in that each sets its priorities differently. Dilthey finds naturalism too reductive; his ethical views incline him toward the idealism of freedom; aesthetically he felt attracted towards objective idealism. No metaphysical formulation can have more than relative validity because it attempts to arrive at a totalization that transcends experience. Literary and poetic expressions of worldviews tend to be more successful because they do not claim to be totalizing. All that is humanly possible is to probe reality on the basis of life-experience and to settle for more limited philosophical insights informed by historical understanding. Ultimately, our reflective understanding of life and history must remain determinate-indeterminate.