Modern Philosophy

Modern Philosophy primarily consists of two schools of thought, Rationalism and Empiricism. Their epistemological discourse varied, with Rationalists claiming reason to be the primary source of all knowledge and empiricists claiming experience to be the primary source instead.

The spirit of modern philosophy emphasized the spirit of independence, and was marked by an awakening of the reflective spirit and quickening of criticism. Further more, there was:

  • Demands for freedom in thought
  • Revolt against absolutism and collectivism
  • Revolt against authority

Focus shifted from contemplation of the supernatural to reflection on natural things. Reason was started to be taken as authority in science and philosophy. For example, the introduction of Heliocentric theory was in this era. Practical application of science in technology and medicine was also observed.

Rationalists and Empiricists debated on the nature of truth as well. Rationalists believed truth to be absolute, and be a priori in nature. The empiricists on the other hand felt truth to be a posteriori in nature, and disagreed that truth was absolute. The empiricists also do not believe in a world beyond our own, such as heaven.

Philosopher School of thought
Francis Bacon Empiricism
Thomas Hobbes Empiricism
Rene Descartes Rationalism
John Locke Empiricism
David Hume Empiricism

   

Francis Bacon

Father of Empiricism

Introduced the method of Induction. He believed that human knowledge must be based on a firm foundation, and emphasized on the importance of social order in science and technology.

His obsession with order led him to be the first to document the Scientific Method. To summarize, the model of knowledge is natural science, the method is induction, and the goal is invention.

The Scientific Method

Novum Organum

The method introduced by Aristotle was teleological, where only the purpose of the object mattered. This method on the other hand utilizes mathematics and methodological observation. (math was ignored before)

Inductive methods are used to deduce mathematical laws. Idolas, or prejudices were encouraged to be ignored for an un-biased observation. Some examples of Idolas are:

  1. Idola of Tribes - general tendencies to be deceived, such as a tendency to overgeneralize
  2. Idola of the den (Specus) - individualistic dispositions regarding education and authority
  3. Idola fori (market) - association of words and names of actual objects
  4. Idola of theatre - result of false theories or philosophies

Induction

Not a case of simple enumeration. Investigate a group of entities with the goal centered around finding out a general cause. Notice that this method is closely related to the cause-effect relationship.

Deductive reasoning is only concerned with intuitively conceptualizing statements, and not about facts. Induction is concerned with utilizing experience obtained by observation to verify facts.

Implicitly, investigation is centered around finding the cause, meaning that a causal relationship was believed.

There are three forms of induction:

  1. Mill’s method of Agreement - Finding out qualities from positive instances

  2. Mill’s method of Difference - Observing that a quality is lost when a form is taken away

  3. Mill’s Concomitant Variation - The object of out inquiry is present in greater or lesser degree

   

Thomas Hobbes

Gave a mechanistic explanation of reality, and tried to utilize science and philosophy practically. He had a heliocentric worldview, and argued in favor of materialistic philosophy.

Thomas Hobbes was an Empiricist.

He believed that faith and feeling had to take a backseat as the source of knowledge.

Theory of Knowledge

He states that senses are the origin of all thoughts - it persists and is retained in memory. Reasoning is a conceptual arithmetic, and thoughts are regulated by desire.

He believed that all knowledge was conditional, and also that the mechanism of body was responsible for senses and mind. (not some metaphysical stuff)

Hobbes tried to impart more practical utility to science and philosophy. He argued in favor of a materialistic philosophy (as opposed to Descartes). He also supported the heliocentric view of Copernicus and Galileo. Hobbes’ theory of knowledge says that reasoning is conceptual arithmetic, with logical addition/subtraction of concepts. The origin of all thoughts is senses, since sensation persists and memory is retained. These thoughts are regulated by desire. The mechanism responsible for causing sensuous experiences is the body.

   

Rene Descartes

“Father of Modern Philosophy”

Rene Descartes was a Rationalist. He didn’t outright reject the notion of god and the metaphysical like Hobbes, rather, he tried to prove the existence of god through logical arguments.

He did believe that faith and feeling had to take a backseat as the source of knowledge, just like Hobbes.

He utilized mathematics as the model for his philosophy. He used both the deductive methods and inductive methods in his works, which is a strength of his theory.

He classified the sciences as follows:

  1. Metaphysics is the principle of knowledge concerning God, immateriality of the soul and all clear and simple ideas that we possess

  2. Physics is the principle of material things, such as the things examined in general

“Philosophy as a whole is like a tree with metaphysics as its roots and physics as its trunk. All other sciences comprise of the branches from this trunk.”

He also followed Methodological Skepticism, where Deductive and Inductive reasoning are used to arrive at a certain and indubitable truth. He was not a skeptic, however, as he wanted to use skepticism to reach certainty.

He doesn’t doubt truth itself, he rather doubts the methods used to arrive at the truths. He states the following as reasons for skepticism:

  • truths in traditional scholastic systems are based on mass-divergent opinions
  • experiences, as senses are deceiving
  • difficult to distinct between dreaming and waking
  • memory can be deceptive
  • evil agents can be deceptive
  • at times, demonstrations of mathematics can be deceptive (calculation mistakes…)

Doubting involves thinking. Therefore, there must be a doubter to doubt. Thus, “I doubt, therefore, I think, therefore, I am.”

“Dubito ergo cogito ergo sum”

Proof for Existence of God

The motive of evils is to deceive. Humans are imperfect, and this implies the existence of a perfect and infinite being. God cannot deceive, since deception is evil and God cannot be evil.

Descartes said that the idea of God is not derived from an external world via senses. That is, God being a perfect being and thus, cannot be caused by the world itself. He felt that senses only affected us, but they did not reveal anything to us. Therefore, he concluded it to be an innate idea or an a priori idea.

Note that Descartes was before Newton, so he did not know how objects moved. It was all attributed to God being an Immovable Mover.

Proof for the Existence of World

We know that the world exists because of our feelings. The feelings of pleasure, pain, hunger and instinctive reactions are all proofs that the external world exists. However, these sensations can be deceiving. Such delusions can be corrected by the power of intellect endowed by god.

Existence of Bodies

Descartes was a dualist, he believed that mind and body were two separate substances which existed independently of one another.

The essence of mind is thought, and the body is divisible whose essence is extension. Descartes firmly states that the mind and body are distinct, and are conceived independently of each other. The occasional causal relationship between mind and body is mediated through the pineal gland.

   

John Locke

He was a Bri’ish empiricist, who did not agree with the ideas presented by Rene Descartes. That is, he did not accept the notion of innate ideas. Instead, he believed that all knowledge is accumulated post-birth via experience. He compared the mind with a blank slate, with knowledge being written on it. He is also well known for his work in proposing the Social Contract theory.

Ideas

He believed there to be two sources of ideas:

  1. Sensation
  2. Reflection

He also categorized ideas into two types; Simple and Complex. Simple Ideas are the ones which enter the mind by only one sense. Complex Ideas on the other hand are received by reflection by the mind on the ideas that it already has.

For example, “something black” is a simple idea. Deducing that the black thing is a crow based on previous experiences and current state is a complex idea.

Some ideas are perceived through both sensation and reflection. Examples include pleasure, pain, power, existence, uneasiness, unity and so on.

Qualities

A quality of an object is the power that it has to produce ideas.

  1. Primary Quality - solidity and extension, inherent in the object
  2. Secondary Quality - sound, taste, colours

Secondary qualities are the qualities of an object which can be changed easily, whereas the primary qualities are relatively not changeable.

Modes

A simple mode consists of variations of the same idea, repeated in different combinations without any mixture of the other. For example, a day or a month is a mode of representing a single idea, namely, time.

Mixed modes are compounded simple ideas of several kinds put together to form a complex one. For example, beauty consists of many factors like colour, figure and so on.

   

David Hume

Hume is an empiricist. He agreed with Descartes, Hobbes and Locke that genuine knowledge must be self-evident, but he finds no such knowledge anywhere other than mathematics, which merely analyses its own concepts. Humes was:

  1. Empirical: knowledge has source in experience
  2. Positivistic: knowledge is limited to world of phenomena
  3. Agnostic: we know nothing of ultimates, substances, soul.etc
  4. Humanistic: human mental world is the only legitimate sphere of inquiry

Hume felt that all sciences had relations to human nature, and subdivided the science of human nature into three:

  1. Logic - Reasoning
  2. Moral and Criticism - tastes and sentiments
  3. Politics - humans are dependent on society

Humes stated that True Metaphysics is the science of understanding, and that moral philosophy provides foundation to all other sciences.

 

Impression and Reflection

All the materials of our thinking are derived from outward/inward impressions. “Impressions” are the more lively perceptions, such as when we hear or see or feel or love, namely all our sensations, passions, and emotions as they make their first appearances in the soul. The inward perceptions are those that are internal (like the sensation of pain or hunger), and the outward perceptions are those that have external origin (like cold or heat). Desire, aversion, hope, and fear are impressions of reflection.

All our thoughts are copies of such impressions. Thoughts are the less lively perceptions such as the faint/feeble perceptions of which we are conscious when we recall/reflect on sensations that arise in the soul from unknown causes, while inward impressions are frequently occasioned by ideas. Knowledge results from compounding the materials due to senses and experiences. We can also associate ideas by observing certain connections, regularities, or contiguities in time/place.

The idea of causation is not reached by any a priori reasoning. The mind cannot deduce the effect from a certain cause, and the study of cause and effect is a study of speculation and practice. We cannot demonstrate that a certain cause has a certain effect. The knowledge of causation is attained through observation and experience. This experience eventually produces a belief, which is an operation of the mind.

All reasoning concerning matters of fact are dependent on cause-and-effect relationships. The evidence is compared with mathematics. The uniformity of nature is a self-evident knowledge (the sun will rise tomorrow). However, even this does not constitute absolute certainty. Hume says that nothing is necessary, and we move from this to probabilities of occurrences instead. Practice is the best cure for skepticism, since being skeptical of everything would lead to no practical good.

Impressions and sensations appear and reappear in our experience. All we can do is to limit ourselves to these, compare our ideas and note their relations, then reasoning about these relations and attaining some kind of demonstrative knowledge. It finally boils down to noticing regularities in observations, leading to a custom, and drawing inferences from them. Passion is the source of understanding the world.

That is, David Hume was a skeptic and he did not believe in the theory of causation.