Critique of Pure Reason

This is a summary of one of the most famous philosophical works, the Critique of Pure Reason by Immanuel Kant. Kant is arguably the most central figure in modern philosophy and his ideas reshaped philosophy forever. Previous to Kant two philosophical camps battled for supremacy, the rationalists who argued that reason was the only true path to knowledge and the empiricists who contended that only information gained from the senses held value. Kant bridged the two contrasting theories in this book, his most famous revolutionary work. The book itself was one of the most difficult books to understand that I've ever read and I'm not entirely sure all of my summary is accurate to what Kant intended, but other summaries on his critique I read seem to share what I surmised so hopefully it's mostly accurate.

Most of early philosophy posited that reason is the ultimate boon and the purest essence of knowledge, morality, and godliness. This book is a critique of the possibility of arriving at what is called “pure knowledge” or knowledge that can be entirely derived from reason alone.

The book starts by identifying that the two types of knowledge, reason and experience, are obtained differently. Reason is knowledge attained previous to experience or completely separate from it while knowledge from experience is only obtained after the experience is had. All knowledge gained before experience is assuming a connection between thing A and thing B, an assumed connection by means of reason, not a tested and tried connection by means of experience. In other words, I could hypothesize all day about whether or not I’d like coco puffs and by the use of reason determine that the possibility is nearly assured due to liking fruit loops, lucky charms, cinnamon toast crunch, and other sugary cereals as well as liking chocolate, but the possibility still remains that I may not go coocoo for coco puffs. Regardless, the assumption that I would like coco puffs without having tried them is an act of reason. Pure reason is able to deduce A as connected to B without any sensory foundation.

The reason why the senses were historically downplayed as a method of obtaining knowledge is because all sensory experiences are determined by the biology and psychology of the individual, which are different from any other being on Earth. Two people can have the exact same experience, such as eating black licorice, but have completely different ideas of what it looks like, tastes likes, smells like, and feels like. Due to its subjectivity and variability, knowledge obtained by the senses was viewed as lacking. On the other hand the empiricists asserted that any knowledge derived from reason was only conjecture and that application and sensory experience was the only method of truly knowing reality.

Kant said that one can't exist without the other.

Kant says that only two things are elements of pure reason, space and time. Neither space nor time can be experienced by any of the five senses. They exist independently of all subjective empirical or sensory experience even though they are also defined by them. Space can only be understood in its relation to another object, a sensory experience, even though space exists on its own, and time is only understood by subjective points of experience that succeed one another, another sensory experience, but it also reasonably exists on its own. They are also the basis upon which all things function, for without a known relationship with time and space at any given moment, we would have no concept of arguably anything. Space and time would conceivably exist whether or not we realized it (emphasis on reason) but we only realize that they exist due to our experiences within them (emphasis on sensory experience).

Concepts are another thing that can be understood by pure reason as determined by judgments, particularly whether or not those judgments are accurate and universal in nature. The concept of a what is a metal, geometry and other concepts that can be understood without direct sensory experience but that have been validated by judgments sustained universally. In other words, based on cause and effect one could reasonably deduce that A leads to B, a deduction gained by sensory input. The concept can be understood without direct experience though which makes it also fit the definition of pure reason. Geometry and ethics are specifically mentioned as pure reason by Kant. Philosophers were kind of obsessed with math for a long time because they valued reason so highly and math is pure reason. Ethics is where philosophy is so interesting to me because philosophers develop really good rational to various ethical positions that are completely opposed to one another. One philosopher named Zeno was renowned for his ability to support one side of an argument and prove it with his points and then the next day do the exact same thing for the opposing side of the argument. Ethics are a fascinating concept that can be developed by reason alone.

One way to determine whether or not a concept is a "true" concept, meaning it is objectively true, is something called the principle of contradiction. The principle of contradiction states that any contradiction to a proposed truth testifies of the falsity of that thing as a truth. Truth has no contradictions and no exceptions. If humans can't read minds but then one human proves that they can, that means that the statement that humans can't read minds is no longer true. The contradiction disproved the concept. Truth holds up invariably to scrutiny without sweeping contrary information under the rug.

Kant advised to think of the antithesis of an idea in order to find its apparent contradictions, similar to the idea posed in the book Think Again by Adam Grant in which he states that the most important question you can ask yourself is "how am I wrong?" Assessing the counter position allows for increased critical thought and refinement of truth as far as it can be determined. It's definitely a useful habit to get into if you care about truth, care about your analysis of ideas, or care about thinking at all. Dialectics are a simple and useful tool to produce higher quality of thought.

Another idea he gave to determine the strength of any given position is to consider betting on it, even hypothetically. It can't be a trivial amount as that doesn't hold sway, but it needs to be an amount that is worth losing. He argued that people generally are very confident in their positions until they consider the strength of their positions in monetary value or similar risk. I would personally argue that being 100% confident in anything almost unilaterally underscores that your position is incorrect. The more confident you are, generally the less you know.

One thing I liked about Kant’s definitions was his use of the word intuition. When he uses the word intuition he means an imagined connection between two things lacking a definitive connection. In many regards it’s synonymous with imagination and he frequently refers to imagination as a key means of attaining pure reason. This is pretty different from our current use of the word intuition as either a subconscious integration of knowledge or spiritually bestowed knowledge which I appreciate because it also merges the two worlds in some ways.

So there you have it, Kant's analysis of pure reason.