Key Ideas
1. Sensible objects are immediately perceived
Colours, sounds, tastes, shapes and textures occur as contents of experience.
2. To be sensible is to be perceived
Berkeley identifies the existence of sensible qualities with their presence to a mind.
3. Heat and pain cannot be separated at intensity
A painful heat cannot plausibly exist as that pain outside every perceiver.
4. Perceived qualities vary relationally
Temperature, taste and colour change with organs, conditions, distance and perspective.
5. Primary qualities are also perceived
Extension, figure and motion cannot be isolated from sensory presentation or variation.
6. An idea can resemble only an idea
Comparison cannot establish resemblance between perception and something wholly unperceived.
7. Material substratum lacks clear content
An unknown “support” explains nothing unless its nature and relation to qualities can be specified.
8. Conceiving the unconceived creates a difficulty
Any object actively imagined is present to a mind during the attempted conception.
9. Ideas are passive
Sensory contents do not perceive or cause themselves.
10. Spirits perceive and will
Minds are active subjects rather than additional items among the ideas they experience.
11. Human imagination does not create nature
The sensory world arrives involuntarily with complexity and order exceeding finite choice.
12. God causes the lawful sensory order
An infinite spirit accounts for regular experience and its independence from individual will.
13. Objects persist without human observation
They remain within God’s perception and the stable system of possible finite experience.
14. Reality differs from imagination
Real ideas are more vivid, coherent, regular and involuntary than privately produced images.
15. A public world is lawfully coordinated
Different minds encounter corresponding experiences because nature follows a common order.
16. Science discovers signs and regularities
Natural laws connect experiences predictively without requiring hidden material powers.
17. Immaterialism claims to defend common sense
The familiar object is what is seen and touched, not an inaccessible duplicate behind perception.
18. Representational matter encourages scepticism
If only ideas are known, resemblance to hidden objects cannot be independently checked.
19. Ordinary language can remain intact
Talk of objects, causes and existence need not carry the philosopher’s theory of material substance.
20. Berkeley joins empiricism with idealism
His insistence upon experiential meaning leads to a reality constituted by ideas and spirits.