Immanuel Kant Epistemology

Thanks:  Tel Asiado

Biography and works of influential German philosopher and teacher Immanuel Kant, best known for 'Critique of Pure Reason.'

Immaneuel Kant is regarded as one of the most influential thinkers of the late 18th century's Enlightened period. He was a German philosopher and professor famous for his three treatises: Critique of Pure Reason, Critique of Practical Reason, and Critique of Judgement.

Early Life of Kant

Immanuel Kant (1724-1804), was born on April 22, 1724, in the Prussian city of Königsberg (now Kalinigrad, Russia). He was not that adventurous and had little interest in music or the arts. His passion was in logic, mathematics and science.

Kant's Three Critiques

Kant's influence primarily comes from the first two of his three Critiques, the Critique of Pure Reason, and the second one, a shorter and more lucid Critique of Practical Reason. The third one, Critique of Judgement, concerned with ideas of beauty and purpose, received less attention.

Critique of Pure Reason

Kant's first critique, Critique of Pure Reason, is considered his greatest work. He was concerned to justify metaphysics as a legitimate subject of inquiry. He set out to determine the limits and correct use of reason, in particular, to bring out into disrepute between the rationalists and the empiricists.

The rationalists claimed that metaphysical judgements – the fundamental principles upon which all knowledge is based – are known and justified purely by the intellect. On the other hand, the empiricists claimed that the human mind is like a blank sheet waiting to be written based upon experience.

Kant tried to find a way to synthesize these two opposing views. His basic insight sprang from the question, "what are the necessary preconditions for having any experience at all?" He argued that in order for human beings to be able to interpret, the human mind had to impose certain structures on its incoming sense-data.

The Categories: Twelve Fundamental Judgements

Kant attempted to define these in terms of twelve fundamental judgements he called the Categories (substance, cause and effect, reciprocity, necessity, possibility, existence, totality, unity, plurality, limitation, reality and negation) which could only be applied within a spatial and temporal framework. Kant claimed that both the Categories and space and time, which he called 'forms of intuition,' were imposed on phenomenal experience by the human mind in order to make sense of it.

Immanuel Kant called his idea of the Categories the 'Copernican revolution.' Like Copernicus, who turned the traditional idea of the sun orbiting the earth on its head, Kant solved the problem of how the mind acquires knowledge from experience by arguing that the mind imposes principles upon experience to generate knowledge.

Critique of Practical Reason

Just as Kant had laid down laws of thought in his first Critique, in his second, Critique of Practical Reason, he set out to deal with problems of ethics. He discussed the relationship between morality and reason, duty, and God. He claimed to have discovered a universal moral law which he called 'the categorical imperative.'

Critique of Judgement

This third book Critique of Judgement contains a discussion of aesthetics, along with the nature of judgements that pertains to what is beautiful.

Kant's Legacy

In addition to his three treatises, Kant produced several essays in support of religious liberalism and enlightenment. He died on February 12, 1804, aged 80. Immanuel Kant claimed to have discovered universal principles of thought applicable to mankind for all time.

Karl Popper

thanks: Tel Asiado

Philosophy of Karl Popper, best known for The Logic of Scientific Discovery, theory of falsificationism, and open society as against totalitarian societies.

Karl Popper (1902-1994) was a Viennese-born British philosopher of science whose principal writings such as Conjectures and Refutations and The Open Society and its Enemies, have been a major influence on 20th century thought. Considered his most important work is The Logic of Scientific Discovery.

Karl Popper’s Theory of Falsificationism

His brand of scientific method, referred to as “falsification” gave rise to a new area of debate in the philosophy of science, and claimed to have solved the “problem of induction” of David Hume.

In falsificationism, Popper claims that the mark of a scientific theory is whether it makes predictions which could in principle serve to falsify it, and that the more predictions a theory makes, “the better it is.” This is part of Popper’s response to what he calls the “myth of induction.”

As characterized by Hume, induction is the method of arriving at theories or generalizations by observing regularities in experience, but he agrees with Hume that any generalization goes beyond the possible evidence for it. However, no number of observed cases of some X having property Y provides the conclusion that all X’s have that property. One simply never observes all X’s to justify this conclusion.

Conjectures of Popper in Answer to Hume’s Induction

Popper’s answer to Hume’s induction problem as criticized by detractors is based on the claim that this characterization first, erroneously assumes that scientific generalizations are conclusions, and secondly, fails to describe accurately the process by which scientists go about forming hypotheses.

He insists that rather than generalizations being conclusions inferred from evidence, they have the logical status of conjectures, that Hume’s problem of induction disappears because generalizations are logically prior, being first conjectured, and then either refuted by experience, (for instance when some X is observed that lacks property Y), or survive to await further observations of X’s. Generations are first conjectured, then held up to the scrutiny of experience for refutation. Experience can never verify a theory as true, rather, only falsify it.

Critics complained that Popper’s theory implicitly employs inductive reasoning, his view being that of a single counter-instance to a hypothesis is enough to falsify it. But this seems to assume that induction is reliable, otherwise a theory falsified in a present time may turn out to be true in the future.

Rationale into Karl Popper’s Philosophy

Popper then rightly claims that universal generalizations, such as “All X’s are Y” are shown false on the occasion of a single X that is not Y, but, he applies his falsification principle to scientific theories as a whole, not just universal statements.

Further, an instance that falsifies “All X’s are Y’s” also confirms the theory “some X’s are Y’s.” Popper's logic of falsification and verification cannot be separated.

Popper finds that the societies advocated by the theory of Marx (communism) and Plato (utopian) are enemies of the “open society.” His influence has given rise to the work of Feyerabend and Kuhn as he fuels debates in philosophy of science.

Wittgenstein Epistemology

Thanks: Tel Asiado

Austrian philosopher Wittgenstein is best known for his early analysis of the language in Tractatus logico-philosophicus and Philosophical Investigations.

Ludwig Wittgenstein is famous for his philosophy of language, and two books, Philosophical Investigations and Tractatus. He was actively involved in the prestigious Vienna Circle, along with friends and colleagues Bertrand Russell and Gottlob Frege.

An Austrian philosopher, Ludwig Josef Johann Wittgenstein (1889-1951) studied engineering in Germany and England and became interested in philosophical analysis and foundations of mathematics. Before earning his doctorate from Cambridge, he became a soldier of the Austrian army during the First World War.

Wittgenstein’s Tractatus

The central theme of Tractatus Logico-Philosophicus (1921), is the relationship between language, thought and reality. Wittgenstein insisted that language is the perceptible form of thought bound to reality by a common logical form. Like Gottlob Frege, he argued that the meaning of linguistic expressions must be determined by the nature of the world, otherwise the sense of expression will be vague and uncertain. From Bertrand Russell, he borrowed the idea that both language and the world must be understood in terms of their constituent parts.

Tractatus is written in the form of numbered paragraphs, often containing one short sentence. It is mainly concerned with the nature of language and its relationship to the world, and outlines his “picture theory” of meaning.

Tractatus is the only book Wittgenstein published in his lifetime. All his other works were published posthumously.

Philosophical Investigations and the Concept of Language-Games

After publication of Tractatus, he went into self-imposed exile and gave away his inherited fortune working in Austria. But by 1929, he became unhappy with his early work and returned to Cambridge. In his absence, however, Tractatus Logico-Philosophicus (1922), won critical acclaim and became a major influence in school of thoughts in Europe.

For 20 years and until the end of his life, be became his own his own strong critic trying to dispel his early thinking. The content of his later writings were posthumously published as Philosophical Investigations (1952).

Wittgenstein remained concern with the nature of language, thought and reality, which his book, Philosophical Investigations, is concerned about. He introduced the idea of “language-games” – that words can only be understood in the context of human activities in which they are used. A language-game constitutes a word and its context of use.

Philosophical Investigations was largely influenced by St. Augustine. Wittgenstein called this common-place concept “the Augustinian picture of language.”

Wittgenstein Influence and Legacy

Ludwig Wittgenstein exerted influence on modern philosophy. In particular, the philosophers of the Vienna Circle and Willard Quine (from Tractatus), J.L. Austin, the Oxford “ordinary language” school of philosophy and the modern speech-act theorists. He was also an acquaintance of Alan Turing, pioneer of computing and artificial intelligence.

David hume Epistemology

Thanks: Beth Walley

Alive between 1711 and 1776, in philosophical terms, David Hume is the hero of modern-day sceptics. His theory was centered on sense impressions.

David Hume renounces all knowledge, except that which can be gained from the senses. Based on this assumption, Hume arrives at the conclusion that all human knowledge is based on 'sense impressions'.

Hume's 'Sense Impressions'

Hume argues that anything that cannot be backed up with evidence should be discarded as purely invention. In this, he denies the existence of God as well as that of logical necessity and causation.

Hume has two primary aims. The first aim is to rid science of any falsehoods which cannot be proven; that is, those beliefs that are based on invention, rather than experience. The second aim, the constructive, is to establish a science of human nature.

With regards to this second point, Hume was very impressed with the way in which Newton had described the physical world in terms of simple mechanical laws. He intended to project this idea onto a system by which he could account for human nature and understanding. He attempts this in his Treaties on Human Nature, a study in experimental psychology, in which Hume searches for general principles. This was entirely discredited. However, Hume's negative program is the perfect example of logical critique, the results of which remain a problem for modern philosophers.

Hume's Illusion of the Self

Hume believed that one never experiences their true self, and that a sense of identity stems from a person’s reaction to everything they experience. As he famously said, "I am nothing but a bundle of perceptions'.

Similarly, Hume notes that causation (the force that compels one event to follow another and so forth) is never experienced in sense impressions. Rather, the concept that the 'cause' must be followed by an effect and so on and so forth, to Hume, is just a projection of human expectation. Therefore, for Hume, there is no reason to suppose that there is any causal necessity in the ordering of events.

Hume's Inductive Reasoning

Hume goes one step further: he suggests that this human belief in causation is just an example of a general psychological state; inductive reasoning. Here, Hume argues that humans naturally make generalisations from observing a number of similar cases. For example, a person who has seen only white swans may seemingly conclude that 'All swans are white'. To Hume, such generalisations are not logically justified because they go beyond individual experience. The logical possibility of black swans always existed, and it was discovered that black swans exist in Australia, for instance.

Since all scientific laws fall into the pattern of observation that Hume outlines with his inductive reasoning, philosophers of science have regarded Hume's philosophy as problematic.

Leibniz: Philosophy and Theodicy

His argument for God, suffering, and his explanation for evil

By: Lucy Gostwick

Leibniz at the University of Leipzig

Born in Leipzig, Leibniz’s father was an established professor of philosophy, who died when he was just six years old. The young Leibniz was a widely recognised as a child prodigy since he had grasped Latin by the age of eight and Greek by the age of twelve. Leibniz started at the University of Leipzig gaining his doctorate in law in 1666.

Early Encounters with Descartes, Spinoza, and Pascal

The early years of his career he spent as a diplomat in France, England and Holland, where he met a number of influential intellectual figures. In Paris he met the mathematicians Renee Descartes and Blaise Pascal, and in London he became acquainted with the chemist Robert Boyle and in Holland, the eminent Spinoza.

Leibniz's Connection to Sir Isaac Newton

He eventually settled in Hanover, devoting his adult life to devising a universal scheme of human knowledge. Leibniz is widely remembered for having discovered a system of calculus, independently to Sir Isaac Newton, which continues to be used today.

Leibniz's Philosophy and the Existence of God

Leibniz, like many thinkers of his time, was a theist - in other words he believed in God. He thought that the universe was composed of substances, chosen and maintained by God. He declared in his Theodicy that God created the world to be the best of all possible worlds, since God, as a benevolent deity, would not have created anything different. This is a difficult assumption for the modern reader to digest, as we are surrounded by examples of evil every day in the news – take 9/11 for example.

Leibniz's Theodicy and the Existence of Evil and Suffering

Leibniz was, however, able to explain the existence of evil by saying that God allows it temporarily for the greater good. Leibniz maintained that everything in the universe was explicable, and labelled this the “principle of sufficient reason”: "There cannot," he wrote, "be any true or existent fact, or any true proposition, without there being a sufficient reason why it should be so and not otherwise" (Monadology, par. 32.) . Thus evil exists in the world for precise reasons. Leibniz argued that we cannot know the effect of removing certain evils in the world since we cannot see the world from an infinite perspective.

These arguments continue amongst theologians and philosophers of religion. For further debates on this subject, see Great thinkers.

Baruch Spinoza Epistemology

Cortesy of Philosphy Pages

Spinoza maintained that human beings do have particular faculties whose functions are to provide some degree of knowledge. I typically assume, for example, that there may be some correlation between thought and extension with regard to sensations produced by the action of other bodies upon my eyes, ears, and fingertips. Even my memory may occasionally harbor some evidence of the order and connection common to things and ideas. And in self-conscious awareness, I seem to achieve genuine knowledge of myself by representing my mind to itself, using ideas to signify other ideas.

Near the end of Book II, then, Spinoza distinguished three kinds of knowledge of which we may be capable: First, opinion, derived either from vague sensory experience or from the signification of words in the memory or imagination, provides only inadequate ideas and cannot be relied upon as a source of truth. Second, reason, which begins with simple adequate ideas and by analyzing causal or logical necessity proceeds toward awareness of their more general causes, does provide us with truth. But intuition, in which the mind deduces the structure of reality from the very essence or idea of god, is the great source of adequate ideas, the highest form of knowledge, and the ultimate guarantor of truth. (II Prop. xl)

Spinoza therefore recommends a three-step process for the achievement of human knowledge: First, disregard the misleading testimony of the senses and conventional learning. Second, starting from the adequate idea of any one existing thing, reason back to the eternal attribute of god from which it derives. Finally, use this knowledge of the divine essence to intuit everything else that ever was, is, and will be. Indeed, he supposed that the Ethics itself is an exercise in this ultimate pursuit of indubitable knowledge.

Absolute Certainty and the Cartesian Circle

by the IEP

Recall that in the First Meditation Descartes supposed that an evil demon was deceiving him. So as long as this supposition remains in place, there is no hope of gaining any absolutely certain knowledge. But he was able to demonstrate God’s existence from intuitively grasped premises, thereby providing, a glimmer of hope of extricating himself from the evil demon scenario. The next step is to demonstrate that God cannot be a deceiver. At the beginning of the Fourth Meditation, Descartes claims that the will to deceive is “undoubtedly evidence of malice or weakness” so as to be an imperfection. But, since God has all perfections and no imperfections, it follows that God cannot be a deceiver. For to conceive of God with the will to deceive would be to conceive him to be both having no imperfections and having one imperfection, which is impossible; it would be like trying to conceive of a mountain without a valley. This conclusion, in addition to God’s existence, provides the absolutely certain foundation Descartes was seeking from the outset of the Meditations. It is absolutely certain because both conclusions (namely that God exists and that God cannot be a deceiver) have themselves been demonstrated from immediately grasped and absolutely certain intuitive truths.

This means that God cannot be the cause of human error, since he did not create humans with a faculty for generating them, nor could God create some being, like an evil demon, who is bent on deception. Rather, humans are the cause of their own errors when they do not use their faculty of judgment correctly. Second, God’s non-deceiving nature also serves to guarantee the truth of all clear and distinct ideas. So God would be a deceiver, if there were a clear and distinct idea that was false, since the mind cannot help but believe them to be true. Hence, clear and distinct ideas must be true on pain of contradiction. This also implies that knowledge of God’s existence is required for having any absolutely certain knowledge. Accordingly, atheists, who are ignorant of God’s existence, cannot have absolutely certain knowledge of any kind, including scientific knowledge.