A Study of Reality Through Descartes, Spinoza, and Leibniz
The study of substance, and metaphysics more generally, aims to define reality and reconcile the conceptual, immaterial aspects of life with the physical manifestations of the cosmos. Seeking to explain the fundamental as well as the universal nature of reality, Descartes, Spinoza, and Leibniz draw a common line of reasoning between their tenets, remain stark in their differences, and prove outspoken deists in an age of rationalism.
As arguably the first significant rationalist of the modern classical period, Descartes first strips reality of every feature but one: that one may only truly know that they themselves are a thinking thing. Through scepticism of the highest degree (invoking finally a malicious demon to counter even mathematical principles), Descartes produces a purely immaterial reality. Yet Descartes also attempts to rebuild the material world in his sixth Meditation. After whittling down reality to a purely immaterial, thinking thing, he then argues for the existence of the physical realm, providing a distinction between the mind and matter, and the divisibility between the two. Although perhaps valid, his arguments do not prove sound, and his reconstruction proves a failure. In arguing for the material world, he explicates that the ideas received by the senses are livelier and “better defined…than any of those which [he] could deliberately and knowingly frame for [himself],” ergo denoting that it is impossible that they proceeded from himself. Similarly, he notes that the sense perceptions that he (as does every individual likewise) experiences, he experiences without consent, and occur outside or beyond himself and therefore cannot flow from his mind. His last major argument for the physical realm is that “God is no deceiver” and would not create the appearance of something material to deceive people into believing in the physical.
For Descartes, the principle of imago dei is both ontologically and epistemologically interpreted. Altering the mediaeval view of the body and the mind, Descartes views the soul as becoming a substance, while yet remaining distinct. From this perspective, the body proves superfluous — the soul necessary. Epistemologically, each idea coming from the human mind is innate to the individual. This compares to God’s causal power, as well as His immaterial cognitive powers. The human consciousness births ideas into existence, an ability only retained by people and their Creator. As to the distinction between mind and matter, he argues that the mind is a substance, one that may be vividly and distinctly comprehended without aid of another material, which includes the physical body. He also elucidates that God is capable of fashioning the mind without the physical, as God Himself is a spiritual being, knowing all, but lacking a body. Since bodies are divisible into various spatial parts and minds (or consciousnesses) do not occupy physical spaces, the mind must be distinct from the body. In other words, bodies produce a physical extension into space in a “non-thinking” way while the thinking mind does not extend into space.
From the arguments that Descartes provides in Meditations VI, the argument of divisibility proves to be the most sound. For what the argument perpetuates is a distinction, and a distinction between material and immaterial at that. The body does occupy space and time, while the human consciousness, although traced back to the brain, is not a specific part located in human heads. The mind is an immaterial substance apart from the body. Descartes successfully establishes this point — and then fails with establishing anything beyond. For Descartes, each individual body and mind is a substance; this starkly contrasts with Spinoza, who claimed that the body and the mind were mere modes.
A dutch, rationalist philosopher, Baruch Spinoza proved one of the early, seminal thinkers of the enlightenment. Spinoza describes the universe around us as containing substances, modes, and attributes. The substances are those from which the attributes flow from and the modes are the modifications of the substances by the body (used as a broad term for senses, actions, et cetera). Substances, according to Spinoza, are independent, conceptually as well as ontologically, and may cause infinite attributes and modes. The substance, in order to birth attributes, would have to necessitate itself and necessarily come into existence. He argues that a substance cannot be finite, for then “it would have to be limited by something else of the same nature, which would also have to exist necessarily, and so there would be two substances of the same attribute, which is absurd.” Ergo, a substance must be infinite and necessary.
He further argues that only one such substance can exist and that a duality (or plurality) of substances cannot logically make sense because if they have nothing in common, then one cannot be the cause of the other. All things must lead to a single cause. Finally, he establishes that God is the only substance and that all creation contains, therefore, the infinite attributes of God. Not only does he declare that God is the substance, he argues that God necessarily must exist because He is the substance with infinite attributes. Spinoza’s definition of substance is vital because it describes an object that is “in itself and is conceived through itself,” requiring no other conception but itself. Through this definition alone, Spinoza has the foundation to argue for the existence of God as that one substance.
Just as properties of a thing define that thing, likewise is the natural world a mirror of God. Yet “God is not literally identical with particular things…rather, these things are simply necessarily and eternally causally generated by (and thus perpetually dependent upon) God.” Spinoza himself clarifies this by defining Natura naturata (natured Nature) as “whatever follows from the necessity of God’s nature, or from any of God’s attributes.” But this is only true for God’s substance and attributes, not for any modes of substance. Spinoza’s substance “denotes, not the whole of nature, but only its active parts;” ergo, Spinoza is no pantheist because he does not see all of Nature as a manifestation of God. However, I do disagree with Nadler’s assertion that Spinoza is an atheist. Rather than read Spinoza as “not elevat[ing] nature into the divine,” Spinoza ought to be read as a naturalistic theist who searches for God through nature. Through natural theology can God be known because all of nature is within God. Spinoza would thus be accurately termed a panentheist — he establishes that God is the only substance and that all creation contains, therefore, the infinite attributes of God. Not only does he declare that God is the substance, he argues that God necessarily must exist because He is the substance with infinite attributes. He believed, instead of diminishing the divine to the status of nature, that nature would lead to the divine and all of creation is contained within God.
This universality is likewise present in Gottfried Wilhelm Leibniz, a mathematician, philosopher, and scientist who wasted not a minute of his life. Substance, for Leibniz, is not complex, but rather simple. Yet, although agreeing with Spinoza that a substance is essentially a unity, he describes them as “being capable of action.” This motion is only possible through force, “that which, in the present, bears with it a change for the future.” Force must be conserved, and, therefore, is “at least one of the requisites for being a substance.” Although Leibniz declared that nothing can exist without God and nothing is self conceived but God, he writes that the material world is infinitely divisible, even past the smallest atom. Each substance has, therefore, a “monad”: a unique and indestructible, immaterial thing that acts, which is the defining attribute of any material object.
The monad, at its core, is the basic unit of consciousness. No one but God is self conceived, yet each object retains a soul that produces action. In this regard does leibniz think in similar terms as Spinoza: in terms of the universality of substance. Similar to Descartes, the body and the soul are substances (and Leibniz will later argue that only the “phenomenon” is truly a substance), but when conceived of in terms of the substance’s connection, all things become substances. For those other substances created by God are “a world by itself, independent of all other things excepting God.” Each object in the world is a substance, as well as each thing related to that substance. This universality approaches Spinoza’s view, although he is similar to Descartes in describing humans as substances rather than mere modes. Reconciling God (or the “phenomenon”) as the singular substance as does Spinoza, Leibniz also affirms Descartes’ conception concerning universality, that each mind and body is interconnected with everything else. Leibniz’s view on the individual as the image of God is primarily epistemological. God remains a necessary existent; furthermore, God remains a self-sufficient Being that depends only on itself for knowledge. Likewise does each individual require only themselves and their rational mind to discover the mysteries of the universe. The person, like God, owns volition and understanding (i.e. a will as well as knowledge), but cannot causally act on the world around them.
Through studying substances and the nature of reality, one can glean insights into the divine, as well as the divine plan for the individual. Just as Descartes and Leibniz affirm the causal and omnipotent hand of God, Spinoza encompasses the universe under one holistic notion of God. And precisely through this search for the divine, especially in relation to material reality, can the individual come to realise the nature of the self. For through the Creator is creation known. Yet the Creator is mysterious; Descartes, Spinoza, and Leibniz all retain disparate views of God — and so do we.
Bibliography
Descartes, René. Meditations on First Philosophy. New York: The Modern Library, 1958.
Descartes, René. Discourse on Method. New York: The Modern Library, 1958.
Leibniz, Wilhelm Gottfried. The Monadology. Dover Publications, 2012.
Nadler, Steven. Interpreting Spinoza; Critical Essays. Cambridge University Press, 2009.
Spinoza, Baruch. Ethics. Penguin Publishing Group, 1996.
