In his Monadology, Leibniz describes the existence and nature of “Monads” or substances. Leibniz believes that it is impossible for there to be any kind of causal interaction between the Monads. Yet, he also states that each Monad reflects the system as a whole, including any change in any other Monad. So then, to explain how it is that this “mirroring” takes place, without the existence of any causal interaction, Leibniz puts forth his Principle of Pre-Established Harmony. The Principle of Pre-Established Harmony states that Monads only appear to interact with each other.
In reality, God created each Monad and programmed it with certain dispositions in such a way that at each instant, the perceptions of each Monad (soul, mind, and body) will always correspond. Leibniz rejects any idea of God intervening in reality, so it is at creation that all Monads were programmed to co-ordinate in reality without need for interference. An example of this would be if one were to be hit in the head with and object, the result would be pain and a physical response like holding ones hand to the wounded area.
In reality the object would not have actually hit the persons head, but only stopped at that point in space and time because it was pre-determined to do so. The mind of the body that was hit would have been pre-determined to have experienced pain at that exact time in history, and the body itself was pre-determined to react physically in the way it did, none of the three things caused or were caused by any of the others. Leibniz principle is best known for being a possible to solution to the mind/body interaction problem that many philosophers of his time were struggling with.
By stating that the entire universe is made up of non-interaction pieces, there is no longer a need to try and explain the minds influence on the body, or vice versa, since there is no actual interaction taking place. However, Leibniz includes all interaction in his principle, explaining all physical casual relationships in the same way. Leibniz’s account for the nature and number of substances differs significantly from Spinoza’s. For Spinoza, there is only one substance in the world: God. Leibniz essentially agrees that there is only one true substance.
However, to Leibniz this substance is the monad, comparable to a soul or spirit, which “is nothing but a simple substance that enters into composites. ” For Leibniz, God exists external to the world of monads, and might be best thought of as a type of “supersubstance” or “supermonad. ” It was God who set the world in motion; therefore, substances depend on God for their existence. Since Leibniz’s God possesses the will to create or destroy substances “in accordance with the principle of the best”, God is the only necessary being.
All other monads, then, depend on Him for their existence, and as such, are non-eternal contingent beings. Spinoza’s pantheism forces the conclusion that all substance is eternal; if it were not eternal, then it would have to be created, which would then violate his definition of substance as something “that the conception of which does not require the conception of another thing from which it has to be formed. ” With respect to final causes, Leibniz and Spinoza also differ greatly. Spinoza, like most other 17th century philosophers, rejected the idea of final causes, however, he alone denied that God could have ends.
He believed that final causes were a construct of the ignorance of man, to justify and refer all the natural phenomena around him. That is to say, man uses the idea of final causes to make that claim that all natural phenomena are directed by God to man’s benefit. Religious preoccupations seem to have guided Leibniz in his attitude toward final causes. Leibniz was one of the few philosophers of his time to defend the idea of final causes. He maintained that Descartes’ antifinalism led to Spinoza’s determinism.
Leibniz argued for the subordination of mechanical to final causes; in addition, he tended to inject final causes also into physics. For Leibniz, the core idea behind the Principle of Pre-Established Harmony required the existence of final causes, to which all of the programming for the Monads would be directed. “Pre-established harmony. ” Wikipedia, The Free Encyclopedia. 20 Feb 2006, 14:33 UTC. 12 Mar 2006, 21:40 . “Purpose. ” Wikipedia, The Free Encyclopedia. 9 Feb 2006, 00:38 UTC. 12 Mar 2006, 21:39 .