1. PHILOSOPHY
Empiricism
When a tree falls in the forest, and no one is there, does it make a sound?

2. John Locke – British (1632-1704)
Tabula Rasa – Mind is blank slate at birth
Everything put there is by experience
No innate ideas
Senses are the main way we experience reality
Reason is a secondary, after the fact part of the equation

3. George Berkely – British (1685-1753)
More empirical than Locke; sense input=reality
If something isn’t sensed, it doesn’t exist“
To be is to be perceived” (to exist)
Existence only occurs when out of sight or sensory range because the perpetual perceiver (God) senses them always.

4. Tree in the forest question?
What would Berkely say about this?
Sound is not in the tree, but in the perceiver
Does the tree even exist w/o an observer?

5. David Hume – British (1711-1776)
Radical Skepticism – what we know about the world is not certain (wrecking ball)
Only two types of ideas
Impression from senses at moment of event (bee sting and I feel pain)
Memory of past impressions (I remember the bee sting, not as intense)

6. When the refrigerator door is closed, the food disappears (what you can not perceive, does not exist)
Anything not sensed is unreal