Pierre Gassendi and Gottfried Leibniz were two philosophers who both discussed ideas of atomism, space, and time. Due to the fact that Gassendi passed away only a couple years after Leibniz was born, the two never conversed amongst each other about the subject.
Coincidentally, Gassendi and Lebniz had a decent amount in common. They were both religious, as Gassendi was a priest and Leibniz belonged to the Lutheran church, and both were scientists. While the two had similar backgrounds which could have provided them with similar ways of thinking and approaching philosophical topics, they disagreed on many philosophical subjects.
One concept that Gassendi and Leibniz had differing beliefs on was space and time. Gassendi believed that time and space are infinite and absolute. Essentially, he believed that these properties were simply modes of existence – they existed boundlessly and can and never will stop. Things exist within space and we need space for things to exist, but space can exist by itself. Similarly, time is endless. The flow of time will never stop no matter what, and even if our universe is destroyed, time will still continue. Time and space predate creation and cannot end or be destroyed. In direct opposition, Leibniz argued for relativity about space and against absolute space. Gassendi believed that space was something that could exist on its own, while Leibniz did not. Leibniz believed that space was a relational entity. Leibniz believed that everything in our reality consists of “monads” (simple substances), and Leibniz did not believe that monads existed in space. Thus, we can conclude that if Leibniz does not believe “monads” exist in space, then he simply considered space an entity in relation to objects. Space was a property that was used to consider and order the position of objects. In regards to time, Leibniz agrees with Gassendi that time is a continuous quality, but he also believes that time is relational, just like space. Basically, he thinks that time only exists as a way to classify and give meaning to something. It is a way to give things order and organize them through their succession. Leibniz believes that if there is nothing or no objects to apply time to, then it does not exist. He also states that time cannot be distinguished from things that exist in time, and therefore, cannot and does not exist on its own. So, while Gassendi believes that time is endless and its own category of existence, independent of other faculties, contrarily, Leibniz believes that time is an entity dependent on objects, and that it can be applied to objects in order to organize them.
Leibniz and Gassendi clashed in regards to their ideas of space and time and they also clashed on ideas of how humans gained knowledge. Gassendi was a firm believer in knowledge coming from sense-experience while Leibniz believed that humans have intuitive knowledge of certain things – there is no way humans could have innate knowledge of all things because we are not Gods.
Gassendi believes that all of our knowledge from the natural world comes to us through sense experience, which is very closely linked to perception. He thinks we are brought into the world with a clear and open mind with no knowledge and learn and develop knowledge as we grow and experience different things. Our senses are our source of knowledge and through our senses we develop perceptions of objects. Leibniz believes that we are born with certain ideas and knowledge in us. He calls these “innate ideas.” He denies that we are born without knowledge, that our mind is a “blank slate.” He denies this theory because of his belief in the principle of sufficient reason – he states that there is no good reason why God would create us with no knowledge already in our minds – he states that God knows it would be more beneficial for us to be born with knowledge instead of born with none, and God only does what is best for us – so there is no way we could be born with a “blank slate.” Leibniz theory of innate ideas directly contrasts Gassendi’s empiricism.
Additionally, Gassendi and Leibniz’s ideas on composition of matter clashed. Gassendi believes in atomism. He thinks that all things are made of atoms, and while there are an incredibly large number of atoms in the universe, there is still a finite number of them. Leibniz believes in monadology. Monadology is the theory that everything is made up of “monads,” which are simple substances that cannot be divided into parts. Leibniz states that monads actually have no parts. With this knowledge, it seems that Leibniz’s monads are very similar to atoms. Yet, one thing Leibniz states about his monads is that they do not exist in space. This differs from Gassendi’s atomism theory because he believes atoms exist everywhere and make up everything, and without space atoms could not exist. Still, a similarity between Gassendi’s and Leibniz’s ideologies is the claim that every object consists of small parts, and at a certain part you will break down an object until you cannot anymore, and you are left with atoms or monads. Another difference between Gassendi and Leibniz in their theories of composition is the limitation of small parts of substances. Gassendi states that there are a finite number of atoms in all objects and thus, a finite number of atoms in the universe. On the other hand, Leibniz states that beings can have an innumerable number of monads – an infinite number of small parts. He states that while there is an infinity of monads and an infinity of their perceptions, we are only conscious of a limited number of those perceptions. It is interesting that Leibniz argues for the infinity of monads while heavily disputing the property of the infinite existence of space and time.
Gassendi and Leibniz practically disagreed on every philosophical topic they both addressed in their writings. Yet, they were both still considered to be two of the most influential philosophers of their time and prime figures in the history of philosophy.
Works Cited
Arthur, Richard T.W. Leibniz on Space, Time, and Relativity. E-book ed., Oxford, Oxford UP, 2021.
Bennett, Jonathan. “Exchange of papers between Leibniz and Clarke.” Early Modern Texts, Mar. 2007, www.earlymoderntexts.com/assets/pdfs/leibniz1715_1.pdf. Accessed 8 Nov. 2022.
Look, Brandon C., “Gottfried Wilhelm Leibniz”, The Stanford Encyclopedia of Philosophy (Spring 2020 Edition), Edward N. Zalta (ed.), URL = <https://plato.stanford.edu/archives/spr2020/entries/leibniz/>.