Nicholas Rescher

Presumption is a remarkably versatile and pervasively useful resource. Firmly grounded in the law of evidence from its origins in classical antiquity, it made its way in the days of medieval scholasticism into the theory and practice of disputation and debate. Subsequently, it extended its reach to play an increasingly significant role in the philosophical theory of knowledge. It has thus come to represent a region where lawyers, debaters, and philosophers can all find some common around. In Presumption and the Practices of Tentative Cognition, Nicholas Rescher endeavors to show that the process of presumption plays a role of virtually indispensable utility in matters of rational inquiry and communication. The origins of presumption may lie in law, but its importance is reinforced by its service to the theory of information management and philosophy.

Pragmatism views theory as embedded in our practices, and develops a normative methodology for evaluating our purposes. Neither theory nor practice are more fundamental: we evaluate practices for efficiently reaching ends, and we re-evaluate ends in light of the possible pursuits appropriate for flourishing human beings. Pragmatism's philosophical anthropology rejects the Humean prioritization of instrumentalist reason. Practical reason encompasses theoretical reasoning, without reducing truth to what is useful. While our warranted conclusions from inquiry are our only criterion for truth, the objective success of our practices and inquiries depend on interacting with nature, not on thought alone

This position is not confined to the philosophical pragmatists of yore. More recent methodologists of science have reacted to Rudolf Carnap’s thesis that science can dispense with accepting hypotheses as true by maintaining that scientists do accept hypotheses, albeit on practical rather than theoretical grounds. On the position adopted by this school of thought, "accepting a hypothesis as true" is to be reinterpreted to amount to "acting or being disposed to act in the manner which would be best relative to a given objective." Accordingly, such theorists propose in effect to reconstrue acceptability-as-true in terms of successful action.

Oft ist gegen den leibnizschen Optimalismus eingewendet worden, dass gerade die Struktur der Mannigfaltigkeit des Möglichen den ganzen Entwurf durchkreuzen könnte. Es wird gesagt, dass es möglicherweise keine beste Welt gibt, weil es mehrere optimale Welten geben könnte. Oder ein anderes Beispiel wäre, dass zu jeder möglichen Welt - egal, wie gut sie ist - eine weitere existiere, die besser ist. Der Beitrag argumentiert, dass Leibniz verschiedene Mittel zur Verfügung standen, um diesen Einwänden überzeugend zu begegnen

Whatever we can appropriately claim about reality has to be presented via a construct built from materials provided by our minds—our thought and deliberation—rather than something mandated unilaterally by reality itself. Our epistemic situation is such that neither reality alone and therefore rigorous realism nor yet our view of it has the entire story to itself. Their entanglement is such that in the end there has to be a negotiation that acknowledges their inseparable interlinkage in the constitution of our knowledge.

Gottfried Wilhelm Leibniz (1646-1716) possessed one of history's great minds. The German philosopher, mathematician, and logician invented (independently of Sir Isaac Newton) calculus. His metaphysics bequeathed a set of problems and approaches that drove the course of Western philosophy, from Kant's eighteenth century until the present day. For over fifty years, the study of Leibniz has been a consistent passion for distinguished philosopher Nicholas Rescher. _On Leibniz_ offers eleven of his essays, written with signature clarity, exploring the aspects of Leibniz's work and life that still resonate in the discipline of philosophy. Rescher's essays are snapshots of Leibniz, lucidly drawn case studies that explain the fundamentals of his ontology: the theory of possible worlds, the world's contingency, space-time frameworks, and intermonadic relationships. Several illuminating pieces reveal Leibniz as a substantial contributor to theories of knowledge. Discussions of his epistemology and methodology, its relationship to John Maynard Keynes and Talmudic scholarship, broaden the traditional view of Leibniz as a uniquely metaphysical thinker. Rescher also explores, in four absorbing biographical essays, Leibniz's scholarly development and professional career in historical context. As a "philosopher courtier" to the Hanoverian court, Leibniz was associated with the leading intellectuals and politicians of his era, including Spinoza, Huygens, Newton, Queen Sophie Charlotte, and Czar Peter the Great. A concluding essay holds up Leibniz's mode of philosophy as a role model for today's scholars. Rescher argues that many current problems can be effectively addressed with principles of process philosophy along lines inspired by Leibniz's monadology. _On Leibniz_ is essential reading for students of Leibniz and Rescher alike.