- John Locke believed that all ideas originate from experience through sensation and reflection. The mind is originally a blank slate (tabula rasa) and knowledge comes only from experience of the external world or internal operations of the mind. - Sensation provides knowledge about external objects like the sun and moon. Reflection provides internal mental awareness, like doubting an outcome or thinking about pizza. Animals can sense external things but may not have the same level of reflective knowledge as humans. - Locke categorized knowledge as intuitive, demonstrative, or sensitive based on the level of certainty involved. Intuitive knowledge involves direct perception of relationships, demonstrative uses reason, and sensitive knowledge lacks the certainty of the first two.

1. Locke revisited

2. Contd.
• Revisiting Locke:
• A) All ideas originate with and from experience.
• B) mind at birth is a clean state. ( Tabula Rasa)
• C) Experience is found in two forms of sensation
and reflection.
• D) Your knowledge about the Sun, the Moon are
all examples of Sensation.
• E) When you doubt about India’s Victory in
cricket, Think about Pizza, It is reflection.

3. Contd.
• F) Realist is somebody who believes that sensation
always stands for something in real world.
• G) Reflection is the internal process by which mind is
aware of its own actions.
• H) Reflection requires higher level of awareness
compared to sensation.
• Question for the class: Animals also have
sensation of Sun, Do they have similar
Knowledge?
• Does Locke answer this question?

4. Contd.
• Complex Idea: Is the sum total of simple parts.
• Following three ideas are simple ideas.
• Idea of Modes: Ideas which are dependent on
others ex. Idea of number,( When we see
three apples or 5 apples we have an idea of
Numbers)

5. Idea of Substance
• A substance is the idea of (substratum) or support underlying a
number of simple qualities experienced together.
• For ex. Certain size, colour, weight, smell, taste etc. go to make an
apple.
• But these qualities cannot exist by them selves.
• Ex. We say a Tall student.
• For the quality of tall- ness to exist, Some thing needs to be their
(In this case student)
• One thing more: Apple is something more than sum of its qualities.
• Question for the class: Can a substance exist
without any qualities?
• Can we define apple as summation of all its
qualities + substratum

6. Idea of Matter
• When Locke comes to give an account of the
qualities of matter, he takes the help of scientific
theory of the day.
• Real quality of matter is not extension but
solidity, which is made up of atoms.
• Primary quantity: Are the fundamental quantity
like solidity figures etc.
• Secondary qualities are like: The impressions
primary quantities have on us. Like smell, taste.
Etc.

7. Contd.
• Primary Quantities exist in their objective
right.
• Secondary Quantities are dependent on the
human objects. To see color we need to have
eyes etc.
• They are also relative, A bucket of water might
be warm for some, Cold for others.

8. Mind
• We get the knowledge of mind through
reflection.
• We know it has the qualities of perceiving,
thinking, memory and willing with the idea of
unknown sub stratum.
• Ex. Your mind says raise your hand. And you do.
Locke is not sure how your mind is able to
command your hand.
• Primary quality of mind is a) Thinking b) Ability to
initiate movement( Raise your hand)

9. Three grades of Knowledge
• Intuitive Knowledge: Some times mind perceives the agreement or
disagreement of two ideas immediately for ex. We know that white
is not black or a circle is not a Triangle.
• This knowledge is more clear and certain and is the highest kind of
knowledge.
• Demonstrative Knowledge: We perceive the agreement or
disagreement between two ideas by intervention of third idea.
• For Ex. A= C and B= C There fore A=B
• Demonstrative knowledge consists in series or chain of Intuitions. It
is inferior to intuitive knowledge.
• Sensitive Knowledge; Anything that comes to acquire the certainty
of demonstrative or intuitive or knowledge is knowledge.
• Any thing less is opinion. Things of which we are not very sure is
called sensitive knowledge. Locke does not find element of
certainty in this knowledge but accepts it.