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Focusing on the idea that all knowledge comes from experience and physical evidence.
Imagine you were born in a room with no windows, no sound, and no way to feel heat or cold. If someone told you 'the sun is hot,' would those words mean anything at all to you?
In the 17th century, philosopher John Locke proposed a revolutionary idea: we are all born as a tabula rasa, which is Latin for a 'blank slate.' This means that when you are born, your mind contains no ideas, no memories, and no knowledge of the world. According to Empiricism, everything you eventually know comes from your five senses. You don't 'just know' that fire is hot or that a circle has no corners; you have to see, touch, or hear about these things first. Every experience you have is like a pen writing on that blank slate, slowly filling your mind with information about reality.
Quick Check
According to the 'tabula rasa' theory, where does a baby's first idea come from?
Answer
It comes from their first sensory experiences, such as touch, sight, or sound.
Empiricists focus on a posteriori knowledge. This is a fancy Latin term that means knowledge gained after (post) an experience. For example, you cannot know if it is raining outside just by sitting in a windowless basement and thinking really hard. You must go outside or look at a weather report to gather evidence. In contrast, some things like are often considered a priori (known through logic alone), but an empiricist would argue you only understand the concept of 'two' because you once saw two physical objects, like two apples or two stones.
1. A child sees a glowing red stove element. 2. The child has no 'inborn' knowledge that red means heat. 3. The child touches the stove and feels pain. 4. Result: The child now has a posteriori knowledge that 'glowing red stoves are hot.' The 'blank slate' has been updated with evidence.
Quick Check
Is the statement 'The cat is on the mat' an example of a priori or a posteriori knowledge?
Answer
A posteriori, because you must observe the cat and the mat to know if it is true.
Empiricism is the heart of the scientific method. Scientists don't just guess how the world works; they use physical evidence to prove it. This process involves making an observation, forming a hypothesis, and then conducting experiments to see if the evidence matches the idea. If the evidence says , the scientist must change their idea, no matter how much they liked it. This relies on the principle of falsifiability: for a claim to be scientific, there must be a way to use evidence to prove it wrong if it isn't true.
1. Observation: You notice plants in the sun look taller than plants in the shade. 2. Hypothesis: If a plant receives 10 hours of light, it will grow centimeters taller than a plant with 5 hours. 3. Experiment: You grow two identical plants, varying only the light. 4. Evidence: You measure the height difference . 5. Conclusion: Your knowledge is now based on measured evidence, not just a feeling.
If all knowledge comes from our senses, what happens when our senses trick us? This is the 'problem of perception.' Think of a straight straw sitting in a glass of water; it looks bent. An empiricist would say we need more evidence to find the truth. We don't just look; we touch the straw to feel it is straight, or we study the physics of light refraction. Empiricism teaches us that while our senses are our only tools for gathering data, we must use the scientific method to double-check that data.
Imagine you are in a desert and see water on the horizon. 1. Initial Evidence: Your eyes detect a shimmering blue surface (Observation A). 2. Conflict: You walk toward it, but the distance never closes (Observation B). 3. New Evidence: You measure the temperature of the air near the ground and find it is much hotter than the air above it. 4. Synthesis: You use the laws of physics to understand that light is bending. 5. Conclusion: You realize your first sensory 'fact' was an illusion, and you correct your 'blank slate' with better, more consistent evidence.
Which philosopher is most famous for the idea of the 'tabula rasa'?
Which of these is an example of 'a posteriori' knowledge?
Empiricists believe that some ideas are 'innate,' meaning we are born already knowing them.
Review Tomorrow
In 24 hours, try to explain the difference between 'a priori' and 'a posteriori' knowledge to a friend or family member using the 'Hot Stove' example.
Practice Activity
Look around your room and pick one object. List three things you know about it that are 'a posteriori' (e.g., its color, its weight, its texture) and think about how you first learned those facts.