Metaphysics

You may ask, what is metaphysics and what is its importance? Although philosophers have come up with many different viewpoint, an accepted definition is that it is the part of philosophy that investigates what is the reality of any particular science and what is beyond reality, or beyond this physical world. Simply put, it is about what is real. It covers the realms of cosmology, ontology and natural science.Cosmic Lighthouse: Metaphysics Metaphysics is an important method for evaluating the rational basis of our assumptions regarding the nature of reality. http://philsci-archive.pitt.edu/archive/00004118/01/Reply_to_Lewis._metaphysics_versus_epistemology.pdf

The philosopher Aristotle wrote extensively about "first philosophy," giving it two definitions: "being as such" and "first causes." Although he did not coin the term metaphysics, his 14 books on this subject were gathered in the text Metaphysics. This book is considered one of the foremost authorities on the subject.http://plato.stanford.edu/entries/metaphysics/

Gottfried Leibniz (1646 - 1716) originated the theory of monadology. He chose a Greek word "monas" that means unity to illustrate the connection of material manifestation and God. He said that "....God alone is the primary Unity, or original simple substance, from which all monads, created and derived, are produced." The monads are in the essence of all matter and are under a constant influence of change. He further postulated that the ultimate reason of things was based on the monad as necessary substance, and that the differentiation of the changes within things was based on their source: God. He did not believe that the solidity of matter was a primary quality. http://www.spaceandmotion.com/Philosophy-Gottfried-Leibniz-Philosopher.htm

Cosmology, particularly rational cosmology, is the development of arguments regarding the nature and make-up of the "world." The world is assumed to the the totality of all objects and events that are observed in space and time. Immanuel Kant, in his "Critique of Pure Reason" rejected rational cosmology on the basis that the idea of the "world" is “pseudo-empirical.” Arguments are relegated subjective features that are intuitive and not rational. http://plato.stanford.edu/entries/kant-metaphysics/

Ontology, in a metaphysical sense, is the study of being. Studies regarding the reality and or existence of God are ontological, concerning questions such evidence and perceived realities of the nature of God. Ontological arguments involve pure thinking of abstract objects to attain conceptual coherence. Arguments do not contain evidence from the senses. www.esu.edu/.../Intro%20to%20Phil,%20Lecture%203,%20Anselm's%20Ontological%20Argument.doc

In computer science where artificial intelligence is being developed, ontology has a different meaning than in philosophy, being a systematic description of the concepts and relationships that can exist between concepts. In short, it is a specification of a conceptualization. This is a more general definition than in cases where ontology is used set-of-concept-definitions. http://www-ksl.stanford.edu/kst/what-is-an-ontology.html

• Aristotle - "The first philosophy (Metaphysics) is universal and is exclusively concerned with primary substance. ... And here we will have the science to study that which is, both in its essence and in the properties which, just as a thing that is, it has."
  
  
• Benedictus de Spinoza - "the logic of One Infinite Substance; No two or more substances can have the same attribute and it appertains to the nature of substance that it should exist. It must therefore exist finitely or infinitely. But not finitely. For it would then be limited by some other substance of the same nature which also of necessity must exist: and then two substances would be granted having the same attribute, which is absurd. It will exist, therefore, infinitely."
  
  
• Immanuel Kant - "Natural science (physics) contains in itself synthetical judgments a priori, as principles. ... Space then is a necessary representation a priori, which serves for the foundation of all external intuitions."
  
  
• David Hume - "We then call the one object, Cause; the other, Effect. We suppose that there is some connection between them; some power in the one, by which it infallibly produces the other, and operates with the greatest certainty and strongest necessity." http://www.spaceandmotion.com/
  
  
• Bertrand Russell - "Although this may seem a paradox, all exact science is dominated by the idea of approximation. When a man tells you that he knows the exact truth about anything, you are safe in inferring that he is an inexact man"

1. The nature of metaphysics
2. The nature of being
3. The first causes of things
4. Things that do not change
5. Space and time (considered before Albert Einstein)
6. Modality - the possibility and necessity of propositions and things
7. Mental vs. Physical relationship
8. Free will vs. Determinism http://www.ucl.ac.uk/~uctytho/dfwIntroIndex.htm
9. Material constitution and identity - does reducing something to its parts define it?http://plato.stanford.edu/entries/metaphysics/

• Wikipedia: Notable Metaphysicians and Critics of Metaphysics