Locke, Berkeley, & Empiricism: Crash Course Philosophy #6

Summary

This Crash Course Philosophy episode explores empiricism as a response to skepticism, focusing on the debate between rationalism and the reliance on sensory experience for knowledge. It discusses Rene Descartes' radical skepticism leading to 'Cogito ergo sum' and John Locke's theory of 'tabula rasa', where all knowledge comes from experience. Locke's distinction between primary and secondary qualities is highlighted, and George Berkeley's idealist conclusion that 'esse est percepi'—'to be is to be perceived'—is examined, ultimately positing God as the Ultimate Perceiver maintaining the existence of all things.

Takeaways

• 🧐 Empiricism is introduced as a philosophical approach that emphasizes the role of the senses as the most reliable source of knowledge, contrasting with rationalism which relies on reason and deduction.
• 🤔 Descartes' skepticism and his famous 'Cogito, ergo sum' (I think, therefore I am) is highlighted as a starting point for building knowledge, despite his focus on immaterial beliefs.
• 📚 John Locke's concept of 'tabula rasa' (blank slate) is presented, suggesting that all knowledge is acquired through experience, rejecting innate ideas.
• 🍏 Locke's distinction between primary and secondary qualities of objects is explained, with primary qualities being inherent to objects and secondary qualities being subjective perceptions.
• 🔍 The script discusses the limitations of relying solely on the senses, as they can sometimes provide false information, a point of agreement between Locke and Descartes.
• 🍎 Locke's example of an apple is used to illustrate primary qualities (weight, size, shape, and motion) and secondary qualities (color, taste, texture, smell, and sound).
• 🔄 George Berkeley's critique of Locke's distinction is presented, arguing that primary and secondary qualities cannot be separated and that all qualities are perceptions.
• 🌀 Berkeley's philosophy, leading to the conclusion that 'esse est percepi' (to be is to be perceived), suggesting that matter does not exist independently of perception.
• 😲 The script raises the existential implications of Berkeley's philosophy, where the cessation of perception could mean the end of existence for objects and even oneself.
• 👼 Berkeley's solution to this conundrum is the belief in God as the Ultimate Perceiver, maintaining the existence of objects even when not perceived by humans.
• 🔮 The episode ends with a teaser for the next part of the series, hinting at Karl Popper's potential to offer a solution to the dilemma posed by Berkeley's idealism.

Q & A

What is the main theme of the Crash Course Philosophy video discussed in the script?

The main theme of the video is the exploration of empiricism as a response to skepticism, focusing on the philosophical ideas of John Locke and George Berkeley, and their impact on understanding the nature of reality and truth.

Who is the philosopher that the video script suggests we might question the reality of, including the apple and the speaker themselves?

The script suggests that through the power of empiricism, we might question the reality of the speaker, the apple, and even the viewer's own existence.

What philosophical stance did Rene Descartes take in response to skepticism, and what was his famous assertion?

Rene Descartes took a rationalist stance in response to skepticism, and his famous assertion was 'Cogito ergo sum' or 'I think, therefore I am'.

What is the difference between rationalism and empiricism as two responses to skepticism?

Rationalism, like that of Descartes and Plato, believes that the most real things in life are ideas known through pure reason, while empiricism, as advocated by John Locke, holds that the most reliable source of knowledge is our senses and experiences.

What did John Locke believe about human knowledge at birth?

John Locke believed that humans are born as a 'tabula rasa' or a blank slate, meaning all knowledge is obtained through experience and not innate.

What is the distinction Locke made between primary and secondary qualities?

Locke distinguished between primary qualities, which are inherent in objects themselves (like solidity, extension, figure, and mobility), and secondary qualities, which are perceived in the mind through the primary qualities (like color, taste, texture, smell, and sound).

How did George Berkeley challenge Locke's distinction between primary and secondary qualities?

Berkeley argued that primary and secondary qualities cannot be separated, as they are inextricably linked in perception, leading him to conclude that there is no such thing as matter, and 'to be is to be perceived'.

What is Berkeley's famous assertion that reflects his philosophical stance on the nature of existence?

Berkeley's famous assertion is 'esse est percepi', which means 'to be is to be perceived', suggesting that existence is solely dependent on perception.

What role does Berkeley believe God plays in maintaining the existence of objects?

Berkeley believed that God is the Ultimate Perceiver, whose constant perception holds objects in existence even when humans are not perceiving them.

What is the potential problem with Berkeley's philosophy according to the script?

The potential problem with Berkeley's philosophy is that it implies the existence of everything is dependent on perception, which contradicts our belief in the physical world's independent existence.

What is the sponsor of the Crash Course Philosophy series mentioned in the script?

The sponsor of the Crash Course Philosophy series is Squarespace, a platform for creating websites, blogs, and online stores.

Outlines

00:00

🕵️ Empiricism and the Nature of Reality

This paragraph introduces the philosophical concepts of empiricism and rationalism as responses to skepticism. It discusses Descartes' radical skepticism leading to 'Cogito ergo sum' and his belief in the immaterial world. Empiricism, represented by John Locke, posits that knowledge comes from sensory experience rather than pure reason. Locke's theory of primary and secondary qualities is introduced, with primary qualities being inherent to objects and secondary qualities being perceptions in the mind. The paragraph also touches on the disagreement between philosophers on the reliability of sensory experience.

05:02

🌱 Berkeley's Idealism: Perception and Existence

This paragraph delves into George Berkeley's idealist philosophy, which takes empiricism to its extreme conclusion. Berkeley challenges Locke's distinction between primary and secondary qualities, arguing that they are inseparable and that both are subjective perceptions. He proposes the principle 'esse est percepi' — 'to be is to be perceived,' suggesting that material objects only exist as perceptions in the mind. Berkeley further posits that God, as the ultimate perceiver, sustains the existence of objects even when they are not being perceived by humans. The summary also mentions the absurd implications of Berkeley's philosophy, such as the cessation of one's own existence upon falling asleep or when one's perception ceases.

Keywords

💡Empiricism

Empiricism is a philosophical approach that asserts that knowledge is primarily derived from sensory experience. In the video, empiricism is presented as a response to skepticism and is contrasted with rationalism. It is the idea that our senses provide the most reliable source of knowledge about the material world, as opposed to innate ideas or pure reason. The video uses the example of John Locke, who believed all knowledge comes from experience, to illustrate empiricism.

💡Rationalism

Rationalism is the philosophical belief that reason and logic are the ultimate sources of knowledge, rather than experience or sensory input. In the script, rationalism is discussed as the opposing view to empiricism, with Descartes being a key figure who believed in the primacy of reason. The video contrasts rationalism with empiricism by highlighting Descartes' conviction that 'Cogito ergo sum' (I think, therefore I am) is a foundational truth derived from reason alone.

💡Cogito ergo sum

This Latin phrase, meaning 'I think, therefore I am,' is a philosophical statement made by René Descartes. It represents the core of his belief that the act of doubting one's own thoughts is proof of one's existence. In the video, this concept is used to illustrate the starting point of Descartes' philosophical journey, which led him to build a system of beliefs based on the certainty of one's own thinking.

💡Tabula Rasa

The term 'tabula rasa,' meaning 'blank slate' in Latin, refers to the concept that individuals are born without innate ideas or knowledge, and that all knowledge is acquired through experience. John Locke is mentioned in the script as a proponent of this idea, arguing against the notion of innate ideas and asserting that all knowledge comes from sensory experience.

💡Primary Qualities

In the script, primary qualities are described as the inherent properties of an object that exist independently of human perception. These include solidity, extension (height, depth, and width), figure (shape), and mobility (whether an object is stationary or in motion). Locke believed these qualities are what physical objects themselves possess, and they are used to differentiate between what is real and what is a product of perception.

💡Secondary Qualities

Secondary qualities, as discussed in the video, are attributes that are not inherent to objects themselves but are perceived by the senses, such as color, taste, texture, smell, and sound. According to Locke, these qualities exist in the mind and arise from the interaction between primary qualities and the senses, highlighting the subjective nature of perception.

💡Skepticism

Skepticism, in the context of the video, refers to a philosophical stance that questions the possibility of obtaining certain knowledge. The script discusses how both empiricism and rationalism emerged as responses to skepticism, with philosophers like Descartes and Locke grappling with the challenge of establishing a reliable foundation for knowledge.

💡George Berkeley

George Berkeley is an Irish philosopher mentioned in the script who took empiricism to its logical extreme, arguing that material substance does not exist independently of the mind. His philosophy, known as idealism, posits that 'esse est percepi' (to be is to be perceived), suggesting that objects only exist as perceptions in the mind, and ultimately, God is the ultimate perceiver maintaining the existence of all things.

💡Perception

Perception is the process by which the senses gather information from the environment and the brain interprets it to understand the world. The video script explores the role of perception in shaping our understanding of reality, particularly in the context of Berkeley's philosophy, where perception is the basis for the existence of objects.

💡God as the Ultimate Perceiver

In the video, Berkeley's philosophy introduces the concept of God as the ultimate perceiver, an entity that perceives all things constantly and thus maintains their existence. This idea is a response to the question of what keeps objects in existence when they are not being perceived by human senses, suggesting that divine perception ensures the continuity of reality.

Highlights

Introduction of the philosophical debate on the nature of reality and the role of empiricism.

Descartes' radical skepticism leading to 'Cogito ergo sum' as a foundational belief.

The distinction between immaterial and material beliefs in Descartes' philosophy.

Critiques of Descartes' 'Cogito' and the argument that thinking alone does not guarantee correspondence to material reality.

The emergence of rationalism and empiricism as responses to skepticism.

Descartes' rationalism emphasizing the primacy of reason and deductive truths.

Empiricism's reliance on sensory experience and the scientific method as sources of knowledge.

The historical debate between Plato and Aristotle on the nature of truth and reality.

John Locke's concept of 'tabula rasa' and the rejection of innate ideas.

Locke's distinction between primary and secondary qualities of objects.

The idea that primary qualities are inherent to objects, while secondary qualities are subjective perceptions.

Berkeley's critique of Locke's distinction and the argument that primary and secondary qualities are inseparable.

Berkeley's conclusion that 'esse est percepi' — to be is to be perceived, implying the non-existence of matter.

The philosophical implication that without constant perception, objects and even perceivers cease to exist.

Berkeley's solution to the problem of existence: the role of God as the Ultimate Perceiver.

The challenge to our belief in the physical world and the sensory experience as a necessity.

Anticipation of Karl Popper's potential resolution to the debate on the existence of the physical world in the next episode.

The educational value of Crash Course Philosophy in exploring empiricism and its philosophical implications.

Sponsorship acknowledgment and promotion of Squarespace for website creation.

Transcripts

Crash Course Philosophy is brought to you by Squarespace.

Squarespace: share your passion with the world.

By the time we’re done today, I just might have you questioning whether this apple is

real or not. Think I can’t do it? Gimme about ten minutes! I might have you wondering

whether I’m a physical object or not.

And the same goes for all of this stuff, and your computer, and Nick behind the camera! And … you!

How? By unleashing the power of empiricism.

[Theme Music]

Last time, we learned about 17th century philosopher Rene Descartes, and how he upended the apple-basket

that was his entire personal belief system, and descended into a radical skepticism, only

to emerge with his conviction that: Cogito ergo sum – I think, therefore I am.

This one idea -- the fact that he was thinking -- or really, the fact that he was doubting

-- allowed him to build back up, one by one, more beliefs that he thought he could rely on.

But in the end, most of the beliefs that Descartes ended up putting back into his intellectual

apple-basket had to do with the immaterial world.

Like, he decided that he could believe that he existed, as a thinking thing.

And he believed that God existed.

Ultimately, he lit upon the idea that some of our thoughts are clear and distinct in

a way that somehow guarantees their truth.

But, a lot of philosophers disagreed. They argued that thinking on its own wasn’t enough.

Like, just because you’re thinking, doesn’t mean that your thoughts correspond to material

reality in any reliable way.

Basically, Descartes’ philosophical opponents thought that the Cogito was a dead end.

So here, we start to see a split between two different understandings of how we can most

reliably get to the nature of reality, and therefore truth. Both were responses to the

constant questioning that is skepticism. On the one hand, there was rationalism.

And on the other: empiricism

Descartes, like Plato long before him, was a lover of reason. He met skepticism with rationalism.

He believed that the most real things in life were ideas -- propositions that can be known through pure reason.

Deductive truths, which we talked about before, fall into this category. And mathematical truths do, too.

But by contrast, empiricism is based on the principle that the most reliable source of

knowledge isn’t our ideas, or our reasoning, but our senses.

Sure, we can know things through deduction and basic logic.

But what actually leads us to truth, or at least gives us our best shot at getting there,

are things like induction, and the scientific method -- ways of thinking that tell us about the material world.

Probably the most famous split among philosophers between these two camps was the life-long

debate between Plato and Aristotle.

Plato was convinced that Truth resided in the immaterial world of Ideas, while Aristotle’s

attention was focused firmly on the ground.

But what about in Descartes’ day? If he was the original prototype of the navel-gazing

philosopher -- a living example of rationalist thinking — then his foil was was the 17th

century English thinker John Locke. This is where he was born.

Locke believed that we’re all born as a tabula rasa, or a blank slate.

He argued that all knowledge is obtained through experience.

He rejected the concept of innate ideas -- the view that we’re born pre-loaded with certain

information, like what’s good versus what’s bad, or what is the nature of God.

Locke thought that we are born knowing nothing.

And instead, all of our knowledge comes to us through sense data.

But one place where Locke agreed with Descartes was in the idea that, just because your senses

tell you something, that doesn’t mean you can trust it.

After all, sometimes your senses give you false information, like when you think you

see or hear something that’s just not there.

Descartes’ response to this, of course, was to just throw out all sense experience

as an unreliable source of knowledge.

But Locke didn’t go that far. Instead, in order to figure out whether the senses accurately

reflect the outside world, he introduced a distinction between what he called the primary

and secondary qualities of all things.

Primary qualities are qualities that physical objects themselves have. They’re not in

our minds, Locke argued -- they’re actually in the stuff. These primary qualities include

things like solidity -- the density, weight, and mass of an object. And also extension

-- the height, depth, and width that a certain thing has. He also included figure, or the

shape of an object, as well as mobility, which is this – whether it’s stationary or in motion.

So primary qualities, Locke said, belong to the thing itself.

Take this apple. It weighs maybe 150 grams, is the size of my palm, roundish, but firm,

with the slightest bit of give, and right now it’s moving through the air.

Those are its primary qualities.

But it has secondary qualities, too.

And by Locke’s standards, they are not real. At least not in any objective, agreed-upon way.

They’re just in our minds. But they get there through the primary qualities.

I’m talking about things like its color, taste, texture, smell, and sound.

The secondary qualities of this apple are its redness, and how it tastes and smells

and feels on my tongue and hand. Even how it sounds when I bite into it.

Locke believed that the distinction between primary and secondary qualities explained

the disagreements that we all have about our perceptions of the outside world.

Like, we could measure this apple in a bunch of ways and all agree on its primary qualities,

but its secondary qualities would no doubt lead to some disputes.

Like, is it really red? What kind of red exactly? Cardinal red? Or carmine red? It’s kind

of dark purple at the top -- or is it just like a dark pink?

What about the sound it made? Would I call that crunchy? Or crispy? Or...bite-y? It’s like, apple sound.

We could argue about that kind of stuff til the cows came home.

But if we disagree about its primary qualities – one of us is simply wrong. Because primary

qualities have nothing to do with you, or me. Instead they have everything to do with the object itself.

Locke’s reasoning was simple, even elegant, extracting a lot of explanatory power out

of very few basic concepts. As a result, it resonated with a lot people.

And one person it resonated strongly with was the Irish philosopher George Berkeley.

He was moved by Locke’s empiricism and took it seriously -- so seriously, in fact, that

ended up using Locke’s own logic against him.

He basically took empiricism to its logical conclusion, dismantling the whole process

of perception to the point that he had to wonder whether anything existed at all.

Berkeley began by taking apart the distinction that Locke made between primary and secondary qualities.

Like, think about this apple again. How do you know its shape?

Locke said that the apple’s shape, as a primary quality, is immediately perceivable.

But Berkeley pointed out that you don’t perceive some qualities of an object, while

totally disregarding others. Like, you can’t detect an apple’s shape without first --

or at least without also -- detecting its color. When you think about it, you can’t detect

any of the primary qualities without also considering the secondary ones.

You can’t see a colorless apple. You can’t feel a textureless apple.

In fact, if you try to strip away the apple’s secondary qualities in an effort to get at

the primary ones, you end up with no apple at all.

Try it: Close your eyes and imagine an apple made of only primary qualities -- so, it has

a certain shape and a certain size, but it doesn’t have any color or texture or taste.

You can’t do it.

You try to imagine it with no color, but really, you’re probably imagining one that’s either

black or white or transparent -- the color of what’s behind it.

And if you try to imagine it as having no texture, you’ll find there’s still a texture

there – it’s just smooth.

Remember: Locke asserted that secondary qualities are not objectively real. They can only be

subjectively perceived. But now, Berkeley has shown that the two are inextricably linked

– you can’t have one without the other.

Which means that primary qualities can’t be real, either. They, too, are just what

your mind makes of things.

So this led Berkeley to a startling conclusion: There’s just no such thing as matter.

There can’t be! Instead, there’s only perceptions.

Berkeley’s famous assertion -- his version of cogito ergo sum --

was esse est percepi: “to be is to be perceived.”

In his opinion, there are no objects, only perceivers – and even then, the perceivers

themselves don’t really have any physical form. They’re just disembodied minds perceiving

things that aren’t really there.

A little bit terrifying when you start thinking about it.

In Berkeley’s scenario, we’re all set adrift in a world of nothing but thought.

What’s scary about it is this, if everything’s just perception, then when the perception

goes away, there can’t be anything left.

So like, please, for the love of Pete, do not turn away from your computer! If you stop

perceiving me, I stop existing!

But, what if maybe you don’t care about me? Still, you’d better not go to sleep,

because as soon as you do, you’ll cease to exist! Because, you won’t be able to

perceive yourself! The only guarantee that you’ll continue to exist in your sleep is

to have a friend watch you when you’re sleeping. Which probably is a non-starter, for a number of reasons.

But in any case, the second your friend blinks, you’re gone!

So in the end, Berkeley believed there was only one thing that kept us --

and everything else -- from disappearing into oblivion.

God. Berkeley believed that God was the Ultimate Perceiver.

God is always watching, with unblinking perception that holds objects in existence even when we’re not paying attention.

The tough thing about Berkeley is, we all pretty much think he has to be wrong.

Very few of us are willing to give up our belief in the physical world — no matter who’s watching.

We are sensory animals! We really need this apple to exist.

Next time, we’re going to take a side journey into the world of knowledge. And then, in

episode 8, we’ll see if Karl Popper can manage to get the physical world back for us.

Today we have learned about empiricism as a response to skepticism. We talked about

John Locke and his distinction between primary and secondary qualities. And we’ve seen

why George Berkeley thinks that distinction ultimately falls apart -- leaving us with

literally nothing but our minds, ideas, and perceptions.

This episode of Crash Course Philosophy is made possible by Squarespace. Squarespace

is a way to create a website, blog or online store for you and your ideas. Squarespace

features a user-friendly interface, custom templates and 24/7 customer support. Try Squarespace

at squarespace.com/crashcourse for a special offer.

Crash Course Philosophy is produced in association with PBS Digital Studios. You can head over

to their channel to check out some amazing shows like Idea Channel, The Art Assignment, and Gross Science

This episode of Crash Course was filmed in the Doctor Cheryl C. Kinney Crash Course Studio

with the help of these awesome people and our equally fantastic graphics team is Thought Cafe.