The Nature of Necessity by Alvin Plantinga

First of all, what is freedom? Freedom: no causal laws and antecedent conditions determine whether I will or will not act. Plantinga uses these tools to deal with the atheologian’s problem of evil. Essence: the instantiation of the above properties. Essential properties: the properties Socrates has in every world he exists.

An essence is a set of world-indexed properties (i.e., that is those which exist in every possible world 77). An essence could also be a set of properties (76). “A state of affairs must be maximal or complete.”įrom this Plantinga gives a fine, if not always lucid, presentation of essence and nature. But not every possible world is a possible state of affairs. A possible world is the way things could have been, a possible state of affairs (44). While such a question seems arcane, it does allow Plantinga to furnish the theist with a number of highly useful concepts and tools, like possible worlds. Is it possible to state general directions for picking out some proposition-call it the kernel proposition with respect to x and P-whose de dicto modal properties determine whether x has P essentially” (30)? The problem: “suppose we are given the object x and a property P. Plantinga begins his survey of modal ontology with a discussion of de re and de dicto statements.ĭe dicto: predicates a modal property of another dictum or proposition (Plantinga 9).ĭe re: x has a certain property essentially. Somebody described this book perfectly: 'I felt like I was up against a Level 97 Boss and I was only Level 70.' The book ends with an appendix on Quine's objection to quantified modal logic.

The first of these, the problem of reconciling the moral perfection and omnipotence of God with the existence of evil, can, he concludes, be resolved, and the second given a sound formulation. In the final chapters Professor Plantinga applies his logical theories to the elucidation of two problems in the philosophy of religion: the Problem of Evil and the Ontological Arguement. The arguement is developed by means of the notion of possible worlds and ranges over key problems including the nature of essence, trans-world identity, negative existential propositions, and the existence of unactual objects in other possible worlds.

This book, one of the first full-length studies of the modalities to emerge from the debate to which Saul Kripke, David Lewis, Ruth Marcus and others have contributed, is an exploraton and defence of the notion of modality 'de re,' the idea that objects have both essential and accidental properties.

The Nature of Necessity by Alvin Plantinga