John Locke's An Essay Concerning Human Understanding explores the origins and types of ideas. Locke argues that ideas originate from either sensation as we perceive the external world through our senses, or reflection as the mind considers its own operations. He categorizes ideas as simple or complex and divides qualities of objects into primary qualities, like shape and size, and secondary qualities like color or smell. While we can be certain of our own existence and use reason to deduce God's existence, true knowledge of external things ultimately depends on our sensory experience.

1. An Essay ConcerningHuman Understanding John Locke

2. IdeasIn General What is the source of Ideas? Claim: The mind has innate ideas All Ideas come from Sensation and Reflection Objects of Sensation External Objects Operations of the Mind (Reflection) The mind

3. IdeasIn General Ideas begin when perception begins Sensation (in the body) creates perception (in the mind) The mind reflects on ideas and creates new objects

4. IdeasSimple Many sensations are perceived at once These sensations are distinct from one another and cannot be broken down into smaller sensations The mind cannot create simple ideas We cannot imagine anything not within the sensible realm

5. IdeasSimple Four Simple Ideas Of One Sense Only (19) Of Multiple Senses (20) Of Reflection Only (21) Of Sensation and Reflection (21-4

6. Qualitiesof Bodies Definition: What in the perceived body causes the ideas in the mind.

7. Qualitiesof Bodies Primary Qualities (24) Secondary Qualities (25)

8. Qualitiesof Bodies Qualities Primary: bulk, figure, number, situation, motion/rest in solid parts Sensible: produced by our experience of an object. Powers: Ability to change another body

9. Knowledge Ideas of qualities are abstract (98) Ideas do not necessarily tells us about the existence of particular things

10. Knowledge Knowledge of our own existence is Intuitive (98 – 99)

11. Knowledge The existence of God is revealed through the use of Reason (99 – 104)

12. Knowledge The existence of other things is revealed through Sensation (104 – 109)

13. Knowledge But we cannot have complete certainty of existence independent of our Senses