Immanuel Kant

© Copyright Peter Crawford 2015


Immanuel Kant (22 April 1724 – 12 February 1804) was a German philosopher.
He is a central figure of modern philosophy, and set the terms by which all subsequent thinkers have had to grapple.
He argued that human perception structures natural laws, and that reason is the source of morality.
His thought continues to hold a major influence in contemporary thought, especially in fields such as metaphysics, epistemology, ethics, political philosophy, and aesthetics.
Kant's major work, the 'Kritik der reinen Vernunft', 1781 - 'Critique of Pure Reason', aimed to unite reason with experience to move beyond what he took to be failures of traditional philosophy and metaphysics.
He hoped to end an age of speculation where objects outside experience were used to support what he saw as futile theories, while opposing the skepticism of thinkers such as Hume.
He stated:

'It always remains a scandal of philosophy and universal human reason that the existence of things outside us ... should have to be assumed merely on faith, and that if it occurs to anyone to doubt it, we should be unable to answer him with a satisfactory proof.'

Kant proposed a "Copernican Revolution-in-reverse", saying that:

'Up to now it has been assumed that all our cognition must conform to the objects; but ... let us once try whether we do not get farther with the problems of metaphysics by assuming that the objects must conform to our cognition.'

In simple terms, Kant pointed out that we all shape our experience of things through the filter of our mind.
The mind shapes that experience, and among other things, Kant believed the concepts of space and time were programmed into the human brain, as was the notion of cause and effect.
We never have direct experience of things, the noumenal world, and what we do experience is the phenomenal world as conveyed by our senses.
These observations summarize Kant's views upon the 'subject–object' problem.
Kant published other important works on ethics, religion, law, aesthetics, astronomy, and history.
These included the 'Kritik der praktischen Vernunft', 1788 (Critique of Practical Reason), the 'Die Metaphysik der Sitten', 1797 - (Metaphysics of Morals), which dealt with ethics, and the 'Kritik der Urteilskraft', 1790 (Critique of Judgment), which looks at aesthetics and teleology. He aimed to resolve disputes between empirical and rationalist approaches.
The former asserted that all knowledge comes through experience; the latter maintained that reason and innate ideas were prior.
Kant argued that experience is purely subjective without first being processed by pure reason.
He also said that using reason without applying it to experience only leads to theoretical illusions.
The free and proper exercise of reason by the individual was a theme both of the Enlightenment, and of Kant's approaches to the various problems of philosophy.
His ideas influenced many thinkers in Germany during his lifetime.
He settled and moved philosophy beyond the debate between the rationalists and empiricists. The philosophers Fichte, Schelling, Hegel and Schopenhauer amended and developed the Kantian system, thus bringing about various forms of German idealism.
He is seen as a major figure in the history and development of philosophy.
German and European thinking progressed after his time, and his influence still inspires philosophical work today.


Immanuel Kant was born in 1724 in Königsberg, Prussia.
His mother, Anna Regina Reuter (1697–1737), was born in Nürnberg.
His father, Johann Georg Kant (1682–1746), was a German harness maker from Memel, at the time Prussia's most northeastern city.
Kant's paternal grandfather, Hans Kant, had emigrated from Scotland to East Prussia, and his father still spelled their family name "Cant".
Kant was the fourth of nine children (four of them reached adulthood).
Baptized 'Emanuel', he changed his name to 'Immanuel' after learning Hebrew.
Young Kant was a solid, albeit unspectacular, student.
He was brought up in a 'Pietist' household that stressed religious devotion, humility, and a literal interpretation of the Bible.
His education was strict, punitive and disciplinary, and focused on Latin and religious instruction over mathematics and science.
Despite his religious upbringing and maintaining a belief in God, Kant was skeptical of religion in later life; various commentators have labelled him agnostic.
It is often held that Kant lived a very strict and predictable life, leading to an oft-repeated story that neighbors would set their clocks by his daily walks.
He never married, but seemed to have a rewarding social life — he was a popular teacher and a modestly successful author even before starting on his major philosophical works.

Kant showed a great aptitude for study at an early age.
He first attended the Collegium Fridericianum.
In 1740, aged 16, he enrolled at the University of Königsberg, where he spent his whole career.
He studied the philosophy of Gottfried Leibniz and Christian Wolff under Martin Knutzen, a rationalist who was also familiar with developments in British philosophy and science and introduced Kant to the new mathematical physics of Isaac Newton.
Knutzen dissuaded Kant from the theory of pre-established harmony, which he regarded as "the pillow for the lazy mind".
His father's stroke and subsequent death in 1746 interrupted his studies.
Kant became a private tutor in the towns surrounding Königsberg, but continued his scholarly research.
In 1747, he published his first philosophical work, 'Thoughts on the True Estimation of Living Forces'.

Early Works

Kant is best known for his work in the philosophy of ethics and metaphysics, but he made significant contributions to other disciplines.
He made an important astronomical discovery about the nature of Earth's rotation, for which he won the Berlin Academy Prize in 1754. 
Kant pointed out in the middle of last century, what had not previously been discovered by mathematicians or physical astronomers, that the frictional resistance against tidal currents on the earth's surface must cause a diminution of the earth's rotational speed.
This immense discovery in Natural Philosophy seems to have attracted little attention -indeed to have passed quite unnoticed among mathematicians, and astronomers, and naturalists, until about 1840, when the doctrine of energy began to be taken to heart.
In 1775 ], Kant wrote his 'General Natural History and Theory of the Celestial Bodies'.
Kant also laid out the Nebular hypothesis, in which he deduced that the Solar System formed from a large cloud of gas, a nebula.
Thus he tried to explain the order of the solar system, which Isaac Newton had explained as imposed from the beginning by God.
Kant also correctly deduced that the Milky Way was a large disk of stars, which he theorized also formed from a (much larger) spinning cloud of gas.
He further suggested that other nebulae might also be similarly large and distant disks of stars.
These postulations opened new horizons for astronomy: for the first time extending astronomy beyond the solar system to galactic and extra-galactic realms.
From then on, Kant turned increasingly to philosophical issues, although he continued to write on the sciences throughout his life.
In the early 1760s, Kant produced a series of important works in philosophy.
'The False Subtlety of the Four Syllogistic Figures', a work in logic, was published in 1762. 
Two more works appeared the following year: 'Attempt to Introduce the Concept of Negative Magnitudes into Philosophy', and 'The Only Possible Argument in Support of a Demonstration of the Existence of God'.
In 1764, Kant wrote 'Observations on the Feeling of the Beautiful and Sublime', and then was second to Moses Mendelssohn in a Berlin Academy prize competition with his Inquiry 'Concerning the Distinctness of the Principles of Natural Theology and Morality' (often referred to as "The Prize Essay").
In 1770, aged 45, Kant was finally appointed Professor of Logic and Metaphysics at the University of Königsberg.
Kant wrote his inaugural dissertation in defense of this appointment.
This work saw the emergence of several central themes of his mature work, including the distinction between the faculties of intellectual thought and sensible receptivity.
To miss this distinction would mean to commit the error of subreption, and, as he says in the last chapter of the dissertation, only in avoiding this error does metaphysics flourish. 
The issue that vexed Kant was central to what 20th-century scholars call "the philosophy of mind".
The flowering of the natural sciences had led to an understanding of how data reaches the brain.
Sunlight falling on an object is reflected from its surface in a way that maps the surface features (color, texture, etc.).
The reflected light reaches the human eye, passes through the cornea, is focused by the lens onto the retina where it forms an image similar to that formed by light passing through a pinhole into a camera obscura.
The retinal cells send impulses through the optic nerve and then they form a mapping in the brain of the visual features of the object.
The interior mapping is not the exterior object, and our belief that there is a meaningful relationship between the object and the mapping in the brain depends on a chain of reasoning that is not fully grounded.
But the uncertainty aroused by these considerations, by optical illusions, mis-perceptions, delusions, etc., are not the end of the problems.
Kant saw that the mind could not function as an empty container, that simply receives data from outside.
Something must be giving order to the incoming data.
Images of external objects must be kept in the same sequence in which they were received.
This ordering occurs through the mind's intuition of time.
The same considerations apply to the mind's function of constituting space for ordering mappings of visual and tactile signals arriving via the already described chains of physical causation.

It is often claimed that Kant was a late developer, that he only became an important philosopher in his mid-50s after rejecting his earlier views.
While it is true that Kant wrote his greatest works relatively late in life, there is a tendency to underestimate the value of his earlier works.
Recent Kantian scholarship has devoted more attention to these "pre-critical" writings and has recognized a degree of continuity with his mature work.

The Silent Decade

At age 46, Kant was an established scholar and an increasingly influential philosopher. 
Much was expected of him.
In correspondence with his ex-student and friend Markus Herz, Kant admitted that, in the Inaugural Dissertation, he had failed to account for the relation between our sensible and intellectual faculties - he needed to explain how we combine sensory knowledge with reasoned knowledge, these being related, but very different processes.
He also credited David Hume with awakening him from "dogmatic slumber" (circa 1771).
Hume had sugested that experience consists only of sequences of feelings, images or sounds.
Ideas such as "cause", goodness, or objects were not evident in experience, so why do we believe in the reality of these ?
Kant felt that reason could remove this skepticism, and he set himself to solving these problems.
He did not publish any work in philosophy for the next 11 years.
Although fond of company and conversation with others, Kant isolated himself.
He resisted friends' attempts to bring him out of his isolation.
When Kant emerged from his silence in 1781, the result was the 'Kritik der reinen Vernunft'. Although now uniformly recognized as one of the greatest works in the history of philosophy, this Kritik was largely ignored upon its initial publication.
The book was long, over 800 pages in the original German edition, and written in a complex style.
It received few reviews, and these granted it no significance.
Kant's former student, Johann Gottfried Herder criticized it for placing reason as an entity worthy of criticism instead of considering the process of reasoning within the context of language and one's entire personality.
Similar to Christian Garve and Johann Georg Heinrich Feder, he rejected Kant's position that space and time possessed a form which could be analyzed.
Additionally, Garve and Feder also faulted Kant's Kritik for not explaining differences in perception of sensations.
Its reception stood in stark contrast to the praise Kant had received for earlier works, such as his Prize Essay and shorter works that preceded the first Kritik.
These well-received and readable tracts include one on the earthquake in Lisbon that was so popular that it was sold by the page.
Prior to the change in course documented in the first Kritik, his books sold well, and by the time he published 'Observations on the Feeling of the Beautiful and Sublime' in 1764 he had become a notable popular author.
Kant was disappointed with the first Kritik's reception.
Recognizing the need to clarify the original treatise, Kant wrote the 'Prolegomena zu einer jeden künftigen Metaphysik, die als Wissenschaft wird auftreten können' in 1783 as a summary of its main views.
Shortly thereafter, Kant's friend Johann Friedrich Schultz (1739–1805) (professor of mathematics) published 'Erläuterungen uber des Herrn Professor Kant Critik der reinen Vernunft' (Konigsberg, 1784), which was a brief but very accurate commentary on Kant's 'Kritik der reinen Vernunft'.
Kant's reputation gradually rose through the latter portion of the 1780s, sparked by a series of important works: the 1784 essay, "Answer to the Question: What is Enlightenment?"; 1785's Groundwork of the Metaphysics of Morals (his first work on moral philosophy); and, from 1786, Metaphysical Foundations of Natural Science.
But Kant's fame ultimately arrived from an unexpected source.
In 1786, Karl Leonhard Reinhold published a series of public letters on Kantian philosophy. 
In these letters, Reinhold framed Kant's philosophy as a response to the central intellectual controversy of the era: the Pantheism Dispute.
Friedrich Jacobi had accused the recently deceased Gotthold Ephraim Lessing (a distinguished dramatist and philosophical essayist) of Spinozism.
Such a charge, tantamount to atheism, was vigorously denied by Lessing's friend Moses Mendelssohn, leading to a bitter public dispute among partisans.
The controversy gradually escalated into a debate about the values of the Enlightenment and the value of reason.
Reinhold maintained in his letters that Kant's 'Kritik der reinen Vernunft' could settle this dispute by defending the authority and bounds of reason.
Reinhold's letters were widely read, and made Kant the most famous philosopher of his era.