17th Century Philosophers: Leibniz, Bacon, Hobbes, Descartes & Spinoza
Leibniz
Biography
Born in Leipzig in 1646, Leibniz entered college at age 15. He studied philosophy, learned mathematics, and completed a doctorate in jurisprudence and law at age 21. He lived vigorously in both the world of thought and action, authoring several significant books, including Theodicy, which addresses the problem of evil. He met Spinoza and became the first president of the Scientific Society of Berlin. His influence declined, and he died in 1716 at age 70.
The Substance
Leibniz was dissatisfied with Descartes and Spinoza’s descriptions of substance. He believed their views distorted human nature, freedom, and the nature of God. He attempted to solve this dilemma by positing a single substance with two knowable attributes: thought and extension. Spinoza’s monism was a pantheism in which God is everything, and everything is part of everything else. Leibniz accepted Spinoza’s theory of a unique substance but presented an original theory that allowed for the individuality of people, the importance of God, and the reality of purpose and freedom in the universe.
Leibniz stated that real, simple substances called monads are the true atoms of nature—the elements of things. Monads differ from atoms in that atoms are bodies with extension, while Leibniz described monads as force or energy. He held that monads constitute their essential substance and possess activity. The substance is the set composed of monads. Monads have no extension, shape, or size; a monad is a metaphysically existing point. True substances are monads, and Leibniz called them souls to emphasize their intangible nature.
Bacon
Born in 1561, Francis Bacon was the son of Nicholas Bacon. At 12, he entered Cambridge. Years later, he was appointed by Queen Elizabeth and King James I as a member of Parliament and the House of Lords. Over the years, he became Attorney General, Lord Keeper, and Lord Chancellor. He died in 1626 at age 65.
Bacon wanted to reform the science and philosophy of his time, which he believed was stagnant. In those days, Aristotelian philosophy dominated, and Bacon was convinced its teachings were mere shadows and phantoms. He sought to discover a method to unveil the secrets of nature, and he was particularly impressed by Galileo’s construction and use of the telescope.
The Methods
Bacon aimed to cleanse the mind’s surface and equip it with new instruments to observe the universe as it truly is. To achieve this, he believed it was necessary to liberate science from the limitations of understanding and develop a new method of observation.
The Goal
Bacon’s ultimate goal was the complete rebuilding of sciences, arts, and all human knowledge.
Mental Idols
Bacon identified four idols of the mind: the idols of the Tribe, the Cave, the Marketplace, and the Theater. These idols distort our knowledge in various ways. The idols of the Tribe are the biases inherent to human nature. The idols of the Cave represent the limitations of individual minds due to personal experiences and education. The idols of the Marketplace arise from the misuse of language and communication. The idols of the Theater are the dogmatic systems of philosophy and thought.
The Inductive Method
Bacon established a new method for acquiring knowledge. He asserted that deriving our ideas from observing things is a safer way to see things as they are.
Hobbes
Born in 1588 in Westport, England, Thomas Hobbes was the son of a vicar. He was fascinated by classical literature and became the tutor of the Count of Devonshire, which allowed him to travel. In Italy, he met Galileo.
Hobbes believed in a method of observation and deduction. He thought that by drawing axioms from observation, the result would provide exact knowledge. He then began a study that reinvigorated the physical nature of man. He is considered the father of modern totalitarianism, and his theory of man and society was based on a mechanistic model.
Bodies in Motion
Hobbes’s philosophy focused on the characteristics of bodies. He identified three types of bodies: physical (e.g., a stone), the human body, and the body politic. All these share the characteristic of movement. He believed everything that exists is corporeal and that the purpose of philosophy is to study bodies in motion. He defined motion as a continuous process of leaving one place and taking another. Only a body in motion can cause a body at rest to move. Similarly, a body in motion tends to continue moving unless stopped by another body.
Hobbes identified two kinds of motion in humans and animals: vital and voluntary. Vital motions, such as breathing, begin at birth and continue throughout life. Voluntary motions, such as walking or talking, are initiated by movements in our minds.
The Mechanistic Approach to Human Thought
The thought process begins when an external body moves and produces a movement within us. The initial impact causes lasting effects, similar to waves in the ocean that continue even after the wind has stopped. The same happens in humans; when we close our eyes, we retain an image of the thing seen. For Hobbes, thought is a sensation of a range. He believed there is a difference between the animal mind and the human mind because humans can represent their feelings with signs or names, making science and philosophy possible. Humans can form words and sentences.
Moral and Political Theory
Hobbes’s approach to political philosophy resembled the method of geometry. He followed all the consequences derived from the premises of his political theory, and most of these premises revolved around his conception of human nature.
Descartes
René Descartes founded modern philosophy in the 17th century, emphasizing the rational capacity of the human mind. Born in Touraine in 1596, he studied mathematics, philosophy, and logic. During these years, he was impressed by the certainty of mathematics compared to philosophy. His major works include Discourse on Method, Meditations on First Philosophy, and Passions of the Soul. He died in 1650 of a fever after waiting until 5 am for an audience with Queen Christina of Sweden in freezing temperatures.
Descartes appreciated poetry, acknowledging its beauty and ability to reveal truth. However, he also believed that poetry alone could not lead to absolute truth. He dedicated his life to the pursuit of intellectual certainty.
Descartes’ Method
Descartes considered mathematics paramount because it allows for the clear, precise, and accurate grasp of truths without extensive reflection. He believed the primary rudiments of human reason were essential for this method. He advocated for using the same method, based on intuition and deduction, in all sciences.
Intuition is an intellectual vision that eliminates doubt, allowing us to grasp clear, immediate, and certain truths. Deduction builds upon existing knowledge to reach new understanding. It starts with a known premise and leads to a previously unknown conclusion. Descartes argued that deduction arrives at truth through a continuous and uninterrupted act of the mind, similar to a syllogism but focusing on the relationship between truths rather than concepts.
Rules of the Method
Descartes spent years developing rules to guide the mind in selecting appropriate starting points for reasoning. These rules are summarized in four precepts:
- Doubt everything and only accept as true what is clearly and distinctly known.
- Divide complex problems into smaller parts and analyze them individually.
- Proceed from simple to complex ideas.
- Review and summarize the entire process to ensure no omissions or errors.
Descartes also emphasized doubt as a fundamental principle, urging us to question everything until its truth is undeniably established. He used doubt as the starting point for building knowledge. His entire method is based on doubt, recognizing that our senses can be deceptive. He illustrated this with the example of a piece of wax that changes under different weather conditions, highlighting that it is the mind, not the senses, that grasps these changes.
Descartes also explored the difficulty of distinguishing sleep from wakefulness, suggesting that we might be dreaming even when we believe we are awake. He introduced the concept of a deceiving genius, a hypothetical evil god who could manipulate our perceptions and make us believe in things that do not exist. However, he ultimately concluded that such a being could not exist because God is necessarily powerful and good, and everything is created by Him.
I Think, Therefore I Am
This famous phrase encapsulates Descartes’ fundamental insight: the only thing we cannot doubt is the fact that we are thinking. If we are thinking, it is because we are doubting, and if we are doubting, it is because we exist.
Spinoza
Biography
Baruch Spinoza was born in Amsterdam in 1632 to a family of Portuguese Jews. He was familiar with the writings of Maimonides. Forced to leave Amsterdam in 1656, he settled in The Hague, where he developed his writing career, culminating in his major work, Ethics. He died of tuberculosis in 1677 at the age of 45. Spinoza was influenced by Descartes’ rationalism and his method.
Method
Spinoza believed that we can achieve accurate knowledge of reality by following the geometrical method. He added to Descartes’ method an emphasis on order and systematic principles and axioms. He proposed developing a geometry of philosophy, a set of axioms or theorems that would explain the entire system of reality. He believed that the theory of nature could be demonstrated and that any clear and distinct idea is true. A complete, systematic ordering of true ideas would provide a true picture of reality.
Spinoza rejected Descartes'”I think, therefore I a” and believed that philosophy should focus on formulating ideas about God. His philosophy begins with the problem of God’s nature and existence.
Monism
For Spinoza, all attributes are interconnected, thus avoiding the problems arising from Cartesian dualism. If there is a single substance, its attributes, though infinite, are ultimately a single attribute. Everything belongs to one idea, and that idea is its “soul.” Therefore, all beings are animated to varying degrees. The order of ideas reflects the order of things, and it is a necessary order: necessity governs everything that happens in nature, and this can be demonstrated in a geometrical order. However, it’s important to note that this “necessity” does not imply a “purpose.” Spinoza considers the efficient cause but not the final cause, as he believed that thinking things happen for a reason is merely a product of the imagination.