John Locke 1632-1704. John Locke a British philosopher Oxford academic and medical researcher his association with Anthony Ashley Cooper (later.

John LockeJohn Locke

1632-17041632-1704

John LockeJohn Locke

a British philosopherOxford academic and medical researcherhis association with Anthony Ashley Cooper (later the

First Earl of Shaftesbury) led him to become a government official charged with collecting information

about trade and colonies, An economic writer, opposition political activist, and finally a revolutionary whose cause ultimately triumphed in

the Glorious Revolution of 1688. Much of his work is characterized by opposition to

authoritarianism.

a British philosopherOxford academic and medical researcherhis association with Anthony Ashley Cooper (later the

First Earl of Shaftesbury) led him to become a government official charged with collecting information

about trade and colonies, An economic writer, opposition political activist, and finally a revolutionary whose cause ultimately triumphed in

the Glorious Revolution of 1688. Much of his work is characterized by opposition to

authoritarianism.

John LockeJohn Locke

This opposition is both on the level of the individual person and on the level of institutions such as government and church.

For the individual, Locke wants each of us to use reason to search after truth rather than simply accept the opinion of authorities or be subject to superstition.

He wants us to proportion assent to propositions to the evidence for them.

On the level of institutions it becomes important to distinguish the legitimate from the illegitimate functions of institutions and to make the corresponding distinction for the uses of force by these institutions.

This opposition is both on the level of the individual person and on the level of institutions such as government and church.

For the individual, Locke wants each of us to use reason to search after truth rather than simply accept the opinion of authorities or be subject to superstition.

He wants us to proportion assent to propositions to the evidence for them.

On the level of institutions it becomes important to distinguish the legitimate from the illegitimate functions of institutions and to make the corresponding distinction for the uses of force by these institutions.

John LockeJohn LockeThe positive side of Locke's anti-authoritarianism is that

he believes that using reason to try to grasp the truth, and determining the legitimate functions of institutions will optimize human flourishing for the individual and society both in respect to its material and spiritual welfare.

This in turn, amounts to following natural law and the fulfillment of the divine purpose for humanity.

Locke's monumental An Essay Concerning Human Understanding concerns itself with determining the limits of human understanding in respect to God, the self, natural kinds and artifacts, as well as a variety of different kinds of ideas.

The positive side of Locke's anti-authoritarianism is that he believes that using reason to try to grasp the truth, and determining the legitimate functions of institutions will optimize human flourishing for the individual and society both in respect to its material and spiritual welfare.

This in turn, amounts to following natural law and the fulfillment of the divine purpose for humanity.

Locke's monumental An Essay Concerning Human Understanding concerns itself with determining the limits of human understanding in respect to God, the self, natural kinds and artifacts, as well as a variety of different kinds of ideas.

John LockeJohn Locke It thus tells us in some detail what one can legitimately

claim to know and what one cannot. Locke also wrote a variety of important political,

religious and educational works including the Two Treatises of Government, the Letters Concerning Toleration, The Reasonableness of Christianity and Some Thoughts Concerning Education.

It thus tells us in some detail what one can legitimately claim to know and what one cannot.

Locke also wrote a variety of important political, religious and educational works including the Two Treatises of Government, the Letters Concerning Toleration, The Reasonableness of Christianity and Some Thoughts Concerning Education.

An Extraordinary TimeAn Extraordinary Time

Locke grew up and lived through one of the most extraordinary centuries of English political and intellectual history.

It was a century in which conflicts between Crown and Parliament and the overlapping conflicts between Protestants, Anglicans and Catholics swirled into civil war in the 1640s.

With the defeat and death of Charles I, there began a great experiment in governmental institutions including the abolishment of the monarchy, the House of Lords and the Anglican church, and the establishment of Oliver Cromwell's Protectorate in the 1650s.

Locke grew up and lived through one of the most extraordinary centuries of English political and intellectual history.

It was a century in which conflicts between Crown and Parliament and the overlapping conflicts between Protestants, Anglicans and Catholics swirled into civil war in the 1640s.

With the defeat and death of Charles I, there began a great experiment in governmental institutions including the abolishment of the monarchy, the House of Lords and the Anglican church, and the establishment of Oliver Cromwell's Protectorate in the 1650s.

An Extraordinary TimeAn Extraordinary Time

The collapse of the Protectorate after the death of Cromwell was followed by the Restoration of Charles II -- the return of the monarchy, the House of Lords and the Anglican Church.

period lasted from 1660 to 1688 and was marked by continued conflicts between King and Parliament and debates over religious toleration for Protestant dissenters and Catholics.

period ends with the Glorious Revolution of 1688 in which James II was driven from England and replaced by William of Orange and his wife Mary.

The collapse of the Protectorate after the death of Cromwell was followed by the Restoration of Charles II -- the return of the monarchy, the House of Lords and the Anglican Church.

period lasted from 1660 to 1688 and was marked by continued conflicts between King and Parliament and debates over religious toleration for Protestant dissenters and Catholics.

period ends with the Glorious Revolution of 1688 in which James II was driven from England and replaced by William of Orange and his wife Mary.

An Extraordinary TimeAn Extraordinary Time

The final period during which Locke lived involved the consolidation of power by William and Mary, and the beginning of William's efforts to oppose the domination of Europe by the France of Louis XIV, which later culminated in the military victories of John Churchill -- the Duke of Marlborough.

The final period during which Locke lived involved the consolidation of power by William and Mary, and the beginning of William's efforts to oppose the domination of Europe by the France of Louis XIV, which later culminated in the military victories of John Churchill -- the Duke of Marlborough.

Essay on Human UnderstandingEssay on Human UnderstandingLocke is often classified as the first of the great English

empiricists (ignoring the claims of Bacon and Hobbes).This reputation rests on Locke's greatest work, the

monumental An Essay Concerning Human Understanding. In writing An Essay Concerning Human Understanding

Locke adopted Descartes' ‘way of ideas’; though it is transformed so as to become an organic part of Locke's philosophy.

Yet, while admiring Descartes, Locke's involvement with the Oxford scientists gave him a perspective which made him critical of the rationalist elements in Descartes' philosophy.

Locke is often classified as the first of the great English empiricists (ignoring the claims of Bacon and Hobbes).

This reputation rests on Locke's greatest work, the monumental An Essay Concerning Human Understanding.

In writing An Essay Concerning Human Understanding Locke adopted Descartes' ‘way of ideas’; though it is transformed so as to become an organic part of Locke's philosophy.

Yet, while admiring Descartes, Locke's involvement with the Oxford scientists gave him a perspective which made him critical of the rationalist elements in Descartes' philosophy.

Essay on Human UnderstandingEssay on Human UnderstandingSome philosophers before Locke had suggested that it

would be good to find the limits of the Understanding, but what Locke does is to carry out this project in detail.

Locke’s Essay presents a detailed, systematic philosophy of mind and thought.

it wrestles with fundamental questions about how we think and perceive, and it even touches on how we express ourselves through language, logic, and religious practices.

In the introduction, entitled The Epistle to the Reader, Locke describes how he became involved in his current mode of philosophical thinking. He relates an anecdote about a conversation with friends that made him realize that men often suffer in their pursuit of knowledge because they fail to determine the limits of their understanding.

Some philosophers before Locke had suggested that it would be good to find the limits of the Understanding, but what Locke does is to carry out this project in detail.

Locke’s Essay presents a detailed, systematic philosophy of mind and thought.

it wrestles with fundamental questions about how we think and perceive, and it even touches on how we express ourselves through language, logic, and religious practices.

In the introduction, entitled The Epistle to the Reader, Locke describes how he became involved in his current mode of philosophical thinking. He relates an anecdote about a conversation with friends that made him realize that men often suffer in their pursuit of knowledge because they fail to determine the limits of their understanding.

Essay on Human UnderstandingEssay on Human Understanding In the four books of the Essay Locke considers the

sources and nature of human knowledge. Book I argues that we have no innate knowledge. (In this he

resembles Berkeley and Hume, and differs from Descartes and Leibniz.) So, at birth, the human mind is a sort of blank slate on which experience writes.

In Book II Locke claims that ideas are the materials of knowledge and all ideas come from experience.

The term ‘idea,’ Locke tells us "...stands for whatsoever is the Object of the Understanding, when a man thinks." (Essay I, 1, 8, p. 47)

Experience is of two kinds, sensation and reflection. One of these -- sensation -- tells us about things and processes in the external world. The other -- reflection -- tells us about the operations of our own minds. Reflection is a sort of internal sense that makes us conscious of the mental processes we are engaged in. Some ideas we get only from sensation, some only from reflection and some from both. Locke has an atomic or perhaps more accurately a corpuscular theory of ideas

In the four books of the Essay Locke considers the sources and nature of human knowledge. Book I argues that we have no innate knowledge. (In this he

resembles Berkeley and Hume, and differs from Descartes and Leibniz.) So, at birth, the human mind is a sort of blank slate on which experience writes.

In Book II Locke claims that ideas are the materials of knowledge and all ideas come from experience.

The term ‘idea,’ Locke tells us "...stands for whatsoever is the Object of the Understanding, when a man thinks." (Essay I, 1, 8, p. 47)

Experience is of two kinds, sensation and reflection. One of these -- sensation -- tells us about things and processes in the external world. The other -- reflection -- tells us about the operations of our own minds. Reflection is a sort of internal sense that makes us conscious of the mental processes we are engaged in. Some ideas we get only from sensation, some only from reflection and some from both. Locke has an atomic or perhaps more accurately a corpuscular theory of ideas

Essay on Human UnderstandingEssay on Human Understanding

Ideas are either simple or complex. We cannot create simple ideas, we can only get them from experience. In this respect the mind is passive. Once the mind has a store of simple ideas, it can combine them into complex ideas of a variety of kinds. In this respect the mind is active.

Thus, Locke subscribes to a version of the empiricist axiom that there is nothing in the intellect that was not previously in the senses -- where the senses are broadened to include reflection.

Book III deals with the nature of language, its connections with ideas and its role in knowledge. Book IV, the culmination of the previous reflections, explains the nature and limits of knowledge, probability, and the relation of reason and faith

Ideas are either simple or complex. We cannot create simple ideas, we can only get them from experience. In this respect the mind is passive. Once the mind has a store of simple ideas, it can combine them into complex ideas of a variety of kinds. In this respect the mind is active.

Thus, Locke subscribes to a version of the empiricist axiom that there is nothing in the intellect that was not previously in the senses -- where the senses are broadened to include reflection.

Book III deals with the nature of language, its connections with ideas and its role in knowledge. Book IV, the culmination of the previous reflections, explains the nature and limits of knowledge, probability, and the relation of reason and faith

Essay on Human UnderstandingEssay on Human Understanding

the relationships among perception, thought, and language. As opposed to accepting the possibility of directly receiving truth, he sees physical science as moving toward truth, but knowledge as psychology.

Outside world--sense perception--ideas--knowledge of ideas--reflection upon those ideas--ideas as signs of real things and words as again removed.

Book III deals with the nature of language, its connections with ideas and its role in knowledge.

Book IV, the culmination of the previous reflections, explains the nature and limits of knowledge, probability, and the relation of reason and faith

the relationships among perception, thought, and language. As opposed to accepting the possibility of directly receiving truth, he sees physical science as moving toward truth, but knowledge as psychology.

Outside world--sense perception--ideas--knowledge of ideas--reflection upon those ideas--ideas as signs of real things and words as again removed.

Book III deals with the nature of language, its connections with ideas and its role in knowledge.

Book IV, the culmination of the previous reflections, explains the nature and limits of knowledge, probability, and the relation of reason and faith

Book IBook I In Book I, Locke lays out the three goals of his

philosophical project: to discover where our ideas come from, to ascertain what it means to have these ideas and what an idea

essentially is, and to examine issues of faith and opinion to determine how we should

proceed logically when our knowledge is limited. He attacks previous schools of philosophy, such as those

of Plato and Descartes, that maintain a belief in a priori, or innate, knowledge.

begins by opposing the idea that we are all born knowing certain fundamental principles, such as “whatever is, is.”

The usual justification for this belief in innate principles is that certain principles exist to which all human beings universally assent.

In Book I, Locke lays out the three goals of his philosophical project: to discover where our ideas come from, to ascertain what it means to have these ideas and what an idea

essentially is, and to examine issues of faith and opinion to determine how we should

proceed logically when our knowledge is limited. He attacks previous schools of philosophy, such as those

of Plato and Descartes, that maintain a belief in a priori, or innate, knowledge.

begins by opposing the idea that we are all born knowing certain fundamental principles, such as “whatever is, is.”

The usual justification for this belief in innate principles is that certain principles exist to which all human beings universally assent.

Book IBook ILocke contends that, on the contrary, no principle is

actually accepted by every human being. Furthermore, if universal agreement did exist about

something, this agreement might have come about in a way other than through innate knowledge.

Locke offers another argument against innate knowledge, asserting that human beings cannot have ideas in their minds of which they are not aware, so that people cannot be said to possess even the most basic principles until they are taught them or think them through for themselves.

Still another argument is that because human beings differ greatly in their moral ideas, moral knowledge must not be innate.

Locke contends that, on the contrary, no principle is actually accepted by every human being.

Furthermore, if universal agreement did exist about something, this agreement might have come about in a way other than through innate knowledge.

Locke offers another argument against innate knowledge, asserting that human beings cannot have ideas in their minds of which they are not aware, so that people cannot be said to possess even the most basic principles until they are taught them or think them through for themselves.

Still another argument is that because human beings differ greatly in their moral ideas, moral knowledge must not be innate.

Book IBook IFinally, Locke confronts the theory of innate ideas (along

the lines of the Platonic Theory of Forms) and argues that ideas often cited as innate are so complex and confusing that much schooling and thought are required to grasp their meaning.

Against the claim that God is an innate idea, Locke counters that God is not a universally accepted idea and that his existence cannot therefore be innate human knowledge.

Finally, Locke confronts the theory of innate ideas (along the lines of the Platonic Theory of Forms) and argues that ideas often cited as innate are so complex and confusing that much schooling and thought are required to grasp their meaning.

Against the claim that God is an innate idea, Locke counters that God is not a universally accepted idea and that his existence cannot therefore be innate human knowledge.

Book IIBook II

Having eliminated the possibility of innate knowledge, Locke in Book II seeks to demonstrate where knowledge comes from.

He proposes that knowledge is built up from ideas, either simple or complex.

Simple ideas combine in various ways to form complex ideas.

Therefore, the most basic units of knowledge are simple ideas, which come exclusively through experience.

Having eliminated the possibility of innate knowledge, Locke in Book II seeks to demonstrate where knowledge comes from.

He proposes that knowledge is built up from ideas, either simple or complex.

Simple ideas combine in various ways to form complex ideas.

Therefore, the most basic units of knowledge are simple ideas, which come exclusively through experience.

Book IIBook II

There are two types of experience that allow a simple idea to form in the human mind: sensation, or when the mind experiences the world outside

the body through the five senses, and reflection, or when the mind turns inward, recognizing ideas about its own functions, such as thinking, willing, believing, and doubting.

Locke divides simple ideas into four categories: ideas we get from a single sense, such as sight or taste; ideas created from more than one sense, such as shape and

size; ideas emerging from reflection; and ideas arising from a combination of sensation and reflection,

such as unity, existence, pleasure, pain, and substance.

There are two types of experience that allow a simple idea to form in the human mind: sensation, or when the mind experiences the world outside

the body through the five senses, and reflection, or when the mind turns inward, recognizing ideas about its own functions, such as thinking, willing, believing, and doubting.

Locke divides simple ideas into four categories: ideas we get from a single sense, such as sight or taste; ideas created from more than one sense, such as shape and

size; ideas emerging from reflection; and ideas arising from a combination of sensation and reflection,

such as unity, existence, pleasure, pain, and substance.

Book IIBook II

Locke goes on to explain the difference between primary and secondary qualities. Ideas of primary qualities—such as texture, number, size,

shape, and motion—resemble their causes.

Ideas of secondary qualities do not resemble their causes, as is the case with color, sound, taste, and odor.

In other words, primary qualities cannot be separated from the matter, whereas secondary qualities are only the power of an object to produce the idea of that quality in our minds.

Locke goes on to explain the difference between primary and secondary qualities. Ideas of primary qualities—such as texture, number, size,

shape, and motion—resemble their causes.

Ideas of secondary qualities do not resemble their causes, as is the case with color, sound, taste, and odor.

In other words, primary qualities cannot be separated from the matter, whereas secondary qualities are only the power of an object to produce the idea of that quality in our minds.

Book IIBook II

Locke devotes much of book II to exploring various things that our minds are capable of, including making judgments about our own perceptions to refine our ideas, remembering ideas, discerning between ideas, comparing ideas to one another, composing a complex idea from two or more simple ideas, enlarging a simple idea into a complex idea by repetition, and abstracting certain simple ideas from an already complex ideas.

Locke devotes much of book II to exploring various things that our minds are capable of, including making judgments about our own perceptions to refine our ideas, remembering ideas, discerning between ideas, comparing ideas to one another, composing a complex idea from two or more simple ideas, enlarging a simple idea into a complex idea by repetition, and abstracting certain simple ideas from an already complex ideas.

Book IIBook II

Locke also discusses complex ideas, breaking them down into four basic types: modes, which are ideas that do not exist in and of

themselves, such as qualities, numbers, and other abstract concepts;

substances, either self-subsisting things (such as a particular man or a sheep) or collections of such things (an army of men or a flock of sheep);

relations, such as father, bigger, and morally good; and

abstract generals, such as “man” or “sheep” in general. Complex ideas are created through three methods: combination, comparison, and abstraction.

Locke also discusses complex ideas, breaking them down into four basic types: modes, which are ideas that do not exist in and of

themselves, such as qualities, numbers, and other abstract concepts;

substances, either self-subsisting things (such as a particular man or a sheep) or collections of such things (an army of men or a flock of sheep);

relations, such as father, bigger, and morally good; and

abstract generals, such as “man” or “sheep” in general. Complex ideas are created through three methods: combination, comparison, and abstraction.

Book IIIBook III

In book III, Locke discusses abstract general ideas.Everything that exists in the world is a particular “thing.” General ideas occur when we group similar particular

ideas and take away, or abstract, the differences until we are left only with the similarities.

We then use these similarities to create a general term, such as “tree,” which is also a general idea.

We form abstract general ideas for three reasons: it would be too hard to remember a different word for every

particular thing that exists, having a different word for everything that exists would obstruct

communication, and the goal of science is to generalize and categorize everything.

In book III, Locke discusses abstract general ideas.Everything that exists in the world is a particular “thing.” General ideas occur when we group similar particular

ideas and take away, or abstract, the differences until we are left only with the similarities.

We then use these similarities to create a general term, such as “tree,” which is also a general idea.

We form abstract general ideas for three reasons: it would be too hard to remember a different word for every

particular thing that exists, having a different word for everything that exists would obstruct

communication, and the goal of science is to generalize and categorize everything.

Book IIIBook III

There is a clear connection between Book II and III in that Locke claims that words stand for ideas.

Locke argues against the notion of essences, a concept that had been widely accepted since at least Plato’s time.

Plato argued that we can only recognize individuals as members of a species because we are aware of the essence of that species—for example, we recognize a particular tree as a tree because we understand what a tree is in its essence.

Locke argues that essences don’t actually exist as ideal entities but are instead nothing more than the abstract, general ideas that we form about the things we observe, things that actually exist in the world.

There is a clear connection between Book II and III in that Locke claims that words stand for ideas.

Locke argues against the notion of essences, a concept that had been widely accepted since at least Plato’s time.

Plato argued that we can only recognize individuals as members of a species because we are aware of the essence of that species—for example, we recognize a particular tree as a tree because we understand what a tree is in its essence.

Locke argues that essences don’t actually exist as ideal entities but are instead nothing more than the abstract, general ideas that we form about the things we observe, things that actually exist in the world.

Book IIIBook III

Human beings decide which differences and similarities they will use to separate and classify particular things into categories—they choose how to define categories rather than discovering the essence of a given species.

Despite having just criticized the traditional concept of essences, Locke decides to adopt the term into his own philosophy and proceeds to distinguish between real essences and nominal essences.Nominal essences are the specific collections of observable

properties from which we create an abstract general idea. For example, we observe similarities between many different individual dogs and from these observations form our idea of what a dog is.

Human beings decide which differences and similarities they will use to separate and classify particular things into categories—they choose how to define categories rather than discovering the essence of a given species.

Despite having just criticized the traditional concept of essences, Locke decides to adopt the term into his own philosophy and proceeds to distinguish between real essences and nominal essences.Nominal essences are the specific collections of observable

properties from which we create an abstract general idea. For example, we observe similarities between many different individual dogs and from these observations form our idea of what a dog is.

Book IIIBook III

Real essences are the invisible structures and arrangements of corpuscles or atoms that allow for those observable properties to be observable in the first place. For example, to return to the case of dogs, if we could fully understand the biological structures and processes that make a dog a dog, whether those would include DNA or other things as well, then we would understand the real essence of dogs. Unlike the nominal essence, the real essence has a basis in reality.

Locke moves on to discuss language, pointing out natural weaknesses and common abuses of language. The most significant problem with words is that they do not immediately and obviously mean the same thing to all people.

Real essences are the invisible structures and arrangements of corpuscles or atoms that allow for those observable properties to be observable in the first place. For example, to return to the case of dogs, if we could fully understand the biological structures and processes that make a dog a dog, whether those would include DNA or other things as well, then we would understand the real essence of dogs. Unlike the nominal essence, the real essence has a basis in reality.

Locke moves on to discuss language, pointing out natural weaknesses and common abuses of language. The most significant problem with words is that they do not immediately and obviously mean the same thing to all people.

Book IIIBook III

This problem has four main causes: a word may imply a very complex idea, the ideas that words stand for may have no constant

standard anywhere in nature to judge them against, the standard that ideas refer to may not be easily known,

and the meaning of a word and the real nature of the thing

referred to by the word may not be exactly the same. Locke also identifies six common abuses:

people often use words without really knowing what these words mean,

people use words inconsistently,

This problem has four main causes: a word may imply a very complex idea, the ideas that words stand for may have no constant

standard anywhere in nature to judge them against, the standard that ideas refer to may not be easily known,

and the meaning of a word and the real nature of the thing

referred to by the word may not be exactly the same. Locke also identifies six common abuses:

people often use words without really knowing what these words mean,

people use words inconsistently,

Book IIIBook III

Locke also identifies six common abuses: people purposefully make terms obscure by using old words for new and

unusual uses or by introducing new terms without defining them, people mistakenly believe that words refer to things rather than ideas, people try to use words incorrectly to change their meaning, and people assume that others know what they are saying when they are not

really being clear. Locke suggests four remedies to counteract the natural shortcomings

and the abuses of language: never use a word without having a clear idea of what it means; try to recognize the same meaning for words as others do so that we can

communicate with a common vocabulary; if there is the slightest chance that the meaning of your words will be

unclear, define your terms; and always use words consistently.

Locke also identifies six common abuses: people purposefully make terms obscure by using old words for new and

unusual uses or by introducing new terms without defining them, people mistakenly believe that words refer to things rather than ideas, people try to use words incorrectly to change their meaning, and people assume that others know what they are saying when they are not

really being clear. Locke suggests four remedies to counteract the natural shortcomings

and the abuses of language: never use a word without having a clear idea of what it means; try to recognize the same meaning for words as others do so that we can

communicate with a common vocabulary; if there is the slightest chance that the meaning of your words will be

unclear, define your terms; and always use words consistently.

Book IVBook IVIn book IV, Locke addresses the nature of

knowledge itself, asking what knowledge is and in what areas we can hope to attain it.

For Locke, knowledge is what the mind is able to perceive through reasoning out the connection, or lack of connection, between any two or more of our ideas.

Because knowledge only has to do with relations between ideas, which are in the mind, the knowledge we are capable of is not actually knowledge of the world itself.

In book IV, Locke addresses the nature of knowledge itself, asking what knowledge is and in what areas we can hope to attain it.

For Locke, knowledge is what the mind is able to perceive through reasoning out the connection, or lack of connection, between any two or more of our ideas.

Because knowledge only has to do with relations between ideas, which are in the mind, the knowledge we are capable of is not actually knowledge of the world itself.

Book IVBook IVLocke identifies four sorts of agreement and

disagreement that reason can perceive to produce knowledge: identity (blue is blue) and diversity (blue is not yellow), relation (two triangles with equal bases located between the

same two parallel lines are equal triangles), coexistence (iron is always susceptible to magnets), and realization that existence belongs to the ideas themselves and

is not in the mind (the idea of God and of the self).Locke distinguishes between three grades or degrees of

knowledge: intuition, when we immediately perceive an agreement or

disagreement the moment the ideas are understood; demonstration, which requires some sort of proof; and sensitive

knowledge, which is about the existence of an external world, roughly resembling the world as we perceive it.

Locke identifies four sorts of agreement and disagreement that reason can perceive to produce knowledge: identity (blue is blue) and diversity (blue is not yellow), relation (two triangles with equal bases located between the

same two parallel lines are equal triangles), coexistence (iron is always susceptible to magnets), and realization that existence belongs to the ideas themselves and

is not in the mind (the idea of God and of the self).Locke distinguishes between three grades or degrees of

knowledge: intuition, when we immediately perceive an agreement or

disagreement the moment the ideas are understood; demonstration, which requires some sort of proof; and sensitive

knowledge, which is about the existence of an external world, roughly resembling the world as we perceive it.

Book IVBook IVLocke argues that we can never really develop a

system of knowledge in natural philosophy. The best that we can do is to observe certain

qualities in the world that tend to occur together on a regular basis.

The kind of connection he demands is the sort that we find between properties occurring together regularly in geometrical figures.

Although he doesn’t seem to think we will ever be able to know more about the true nature of things,

Locke is hopeful that we can understand existence, and the properties of things that exist in the world, much more thoroughly.

Locke argues that we can never really develop a system of knowledge in natural philosophy.

The best that we can do is to observe certain qualities in the world that tend to occur together on a regular basis.

The kind of connection he demands is the sort that we find between properties occurring together regularly in geometrical figures.

Although he doesn’t seem to think we will ever be able to know more about the true nature of things,

Locke is hopeful that we can understand existence, and the properties of things that exist in the world, much more thoroughly.

Book IVBook IVLocke outlines three strategies for dealing with

the problem of skepticism, or doubt about whether the world exists outside of our minds.

This problem arises naturally from Locke’s theory of knowledge.

If we only have access to the ideas in our minds, which only exist in our minds, how do we know there is a real world outside of our minds?

Locke’s first strategy is to refuse to take the skeptic seriously. Can anyone really doubt, he asks, that there is an

external world out there?

Locke outlines three strategies for dealing with the problem of skepticism, or doubt about whether the world exists outside of our minds.

This problem arises naturally from Locke’s theory of knowledge.

If we only have access to the ideas in our minds, which only exist in our minds, how do we know there is a real world outside of our minds?

Locke’s first strategy is to refuse to take the skeptic seriously. Can anyone really doubt, he asks, that there is an

external world out there?

Book IVBook IVHis second strategy is to say that it doesn’t matter

whether we doubt the existence of an outside world or not.

All that matters is that we know enough to enable us to get around in the world.

His third line of attack involves seven marks of our experience that can best be explained by the existence of an external world: there is a certain realness and strength of clarity to

perception of an immediate object that memories or products of the imagination do not have,

we cannot get these ideas without the sense organ appropriate to them,

we are able to receive ideas of this sort only in certain situations so it cannot be the organs themselves that are responsible for producing the ideas,

His second strategy is to say that it doesn’t matter whether we doubt the existence of an outside world or not.

All that matters is that we know enough to enable us to get around in the world.

His third line of attack involves seven marks of our experience that can best be explained by the existence of an external world: there is a certain realness and strength of clarity to

perception of an immediate object that memories or products of the imagination do not have,

we cannot get these ideas without the sense organ appropriate to them,

we are able to receive ideas of this sort only in certain situations so it cannot be the organs themselves that are responsible for producing the ideas,

Book IVBook IVwe receive ideas passively, some ideas are accompanied by pleasure or pain but the

memories of those ideas are not, our senses often bear witness to the truth of each other’s

reports, and two different people can share the same experience.

Locke argues that almost all of science, with the exception of mathematics and morality, and most of our everyday experience is subject to opinion or judgment.

We base our judgments on the similarity between propositions to our own experience and to the experiences we have heard described by others.

we receive ideas passively, some ideas are accompanied by pleasure or pain but the

memories of those ideas are not, our senses often bear witness to the truth of each other’s

reports, and two different people can share the same experience.

Locke argues that almost all of science, with the exception of mathematics and morality, and most of our everyday experience is subject to opinion or judgment.

We base our judgments on the similarity between propositions to our own experience and to the experiences we have heard described by others.

Book IVBook IVLocke examines the relation between reason and faith. He defines reason as being the faculty we use to

obtain judgment and knowledge. Faith is the acceptance of revelation and has its own

truths, which reason cannot discover. Reason, however, must always be used to determine

which revelations truly are revelations from God and which are the constructions of man.

Finally, Locke divides all of human understanding into three sciences: natural philosophy, or the study of things to gain knowledge; ethics, or the study of how it is best to act; and logic, or the study of words and signs.

Locke examines the relation between reason and faith. He defines reason as being the faculty we use to

obtain judgment and knowledge. Faith is the acceptance of revelation and has its own

truths, which reason cannot discover. Reason, however, must always be used to determine

which revelations truly are revelations from God and which are the constructions of man.

Finally, Locke divides all of human understanding into three sciences: natural philosophy, or the study of things to gain knowledge; ethics, or the study of how it is best to act; and logic, or the study of words and signs.

Locke’s ContributionLocke’s ContributionLocke effectively shifted the focus of seventeenth-

century philosophy from metaphysics to the more basic problems of epistemology, or how people are able to acquire knowledge and understanding.

Locke rigorously addresses many different aspects of human understanding and of the mind’s functions.

His most striking innovation in this regard is his rejection of the theory that human beings are born possessing innate knowledge, which philosophers such as Plato and Descartes had sought to prove.

Locke effectively shifted the focus of seventeenth-century philosophy from metaphysics to the more basic problems of epistemology, or how people are able to acquire knowledge and understanding.

Locke rigorously addresses many different aspects of human understanding and of the mind’s functions.

His most striking innovation in this regard is his rejection of the theory that human beings are born possessing innate knowledge, which philosophers such as Plato and Descartes had sought to prove.

Locke’s ContributionLocke’s ContributionLocke replaces the theory of innate knowledge with his

own signature concept, the tabula rasa, or blank slate.Locke tries to demonstrate that we are born with no

knowledge whatsoever— we are all blank slates at birth—and that we can only know that things exist if we first experience them.

Locke presents “simple” ideas as a basic unit of human understanding, claiming that we can break all of our experiences down into these simple, fundamental parts that cannot be broken down any further.

Locke replaces the theory of innate knowledge with his own signature concept, the tabula rasa, or blank slate.

Locke tries to demonstrate that we are born with no knowledge whatsoever— we are all blank slates at birth—and that we can only know that things exist if we first experience them.

Locke presents “simple” ideas as a basic unit of human understanding, claiming that we can break all of our experiences down into these simple, fundamental parts that cannot be broken down any further.

Locke’s ContributionLocke’s ContributionFor example, the idea of a plain wooden chair can be

broken down into simpler units that are received by our minds through one sense, through multiple senses, through reflection, or through a combination of sensation and reflection.

“Chair” is thus perceived and understood by us in several ways: as brown, as hard, as according to its function (to be sat upon), and as a certain shape that is unique to the object “chair.”

These simple ideas allow us to understand what “chair” is and to recognize it when we come in contact with it.

For example, the idea of a plain wooden chair can be broken down into simpler units that are received by our minds through one sense, through multiple senses, through reflection, or through a combination of sensation and reflection.

“Chair” is thus perceived and understood by us in several ways: as brown, as hard, as according to its function (to be sat upon), and as a certain shape that is unique to the object “chair.”

These simple ideas allow us to understand what “chair” is and to recognize it when we come in contact with it.

Locke’s ContributionLocke’s ContributionLocke’s theory of primary and secondary qualities is

based on the Corpuscular Hypothesis of Robert Boyle, Locke’s friend and contemporary.

According to the Corpuscular Hypothesis, which Locke considered the best scientific picture of the world in his day, all matter is composed of tiny particles, or corpuscles, which are too small to see individually and which are colorless, tasteless, soundless, and odorless.

The arrangement of these invisible particles of matter gives an object of perception both its primary and secondary qualities.

An object’s primary qualities include its size, shape, and movement.

Locke’s theory of primary and secondary qualities is based on the Corpuscular Hypothesis of Robert Boyle, Locke’s friend and contemporary.

According to the Corpuscular Hypothesis, which Locke considered the best scientific picture of the world in his day, all matter is composed of tiny particles, or corpuscles, which are too small to see individually and which are colorless, tasteless, soundless, and odorless.

The arrangement of these invisible particles of matter gives an object of perception both its primary and secondary qualities.

An object’s primary qualities include its size, shape, and movement.

Locke’s ContributionLocke’s ContributionThey are primary in the sense that these qualities exist

regardless of whether anyone perceives them.Secondary qualities include color, odor, and taste, and

they are secondary in the sense that they may be perceived by observers of the object, but they are not inherent in the object.

For example, a rose’s shape and the way it grows are primary because they exist regardless of whether they are observed, but the rose’s redness only exists for an observer under the right conditions of lighting and if the observer’s eyesight is functioning normally.

Locke suggests that because we can explain everything using the existence only of corpuscles and primary qualities, we have no reason to think that secondary qualities have any real basis in the world.

They are primary in the sense that these qualities exist regardless of whether anyone perceives them.

Secondary qualities include color, odor, and taste, and they are secondary in the sense that they may be perceived by observers of the object, but they are not inherent in the object.

For example, a rose’s shape and the way it grows are primary because they exist regardless of whether they are observed, but the rose’s redness only exists for an observer under the right conditions of lighting and if the observer’s eyesight is functioning normally.

Locke suggests that because we can explain everything using the existence only of corpuscles and primary qualities, we have no reason to think that secondary qualities have any real basis in the world.

Locke’s ContributionLocke’s ContributionAccording to Locke, every idea is an object of some

action of perception and thinking. An idea is an immediate object of our thoughts,

something we perceive and to which we are actively paying attention.

We also perceive some things without ever thinking about them, and these things do not continue to exist in our minds because we have no reason to think about them or remember them.

The latter are nonimmediate objects. When we perceive an object’s secondary qualities, we are actually perceiving something that does not exist outside of our minds.

According to Locke, every idea is an object of some action of perception and thinking.

An idea is an immediate object of our thoughts, something we perceive and to which we are actively paying attention.

We also perceive some things without ever thinking about them, and these things do not continue to exist in our minds because we have no reason to think about them or remember them.

The latter are nonimmediate objects. When we perceive an object’s secondary qualities, we are actually perceiving something that does not exist outside of our minds.

Locke’s ContributionLocke’s Contribution In each of these cases, Locke would maintain that the

act of perception always has an internal object—the thing that is perceived exists in our mind.

Moreover, the object of perception sometimes exists only in our minds.

One of the more confusing aspects of Locke’s discussion is the fact that perception and thinking are sometimes, but not always, the same action.

To add to the confusion, Locke claims in Book II that an action of perception may have a nonimmediate object, not that it must have one.

This makes it difficult to pin down a rule for what perception is and isn’t, and how perception works.

In each of these cases, Locke would maintain that the act of perception always has an internal object—the thing that is perceived exists in our mind.

Moreover, the object of perception sometimes exists only in our minds.

One of the more confusing aspects of Locke’s discussion is the fact that perception and thinking are sometimes, but not always, the same action.

To add to the confusion, Locke claims in Book II that an action of perception may have a nonimmediate object, not that it must have one.

This makes it difficult to pin down a rule for what perception is and isn’t, and how perception works.

Locke’s ContributionLocke’s ContributionWe may find Locke’s discussion of essence, or

substance, confusing because Locke himself doesn’t seem convinced of its existence.

Locke may have chosen to retain this concept for several possible reasons.

First, he seems to think that the idea of essence is necessary to make sense of our language.

Second, the concept of essence solves the problem of persistence through change: that is, if a tree is just a bundle of ideas such as “tall,” “green,” “leaves,” and so on, what happens when a tree is short and leafless?

We may find Locke’s discussion of essence, or substance, confusing because Locke himself doesn’t seem convinced of its existence.

Locke may have chosen to retain this concept for several possible reasons.

First, he seems to think that the idea of essence is necessary to make sense of our language.

Second, the concept of essence solves the problem of persistence through change: that is, if a tree is just a bundle of ideas such as “tall,” “green,” “leaves,” and so on, what happens when a tree is short and leafless?

Locke’s ContributionLocke’s ContributionDoes this new collection of qualities change the

essence from “tree” to something new? In Locke’s view, the essence persists through any

change, remaining the same despite changes in the object’s properties.

A third reason Locke seem to be compelled to accept the notion of essence is to explain what unifies ideas that occur at the same time, making them into a single thing, distinct from any other thing.

Essence helps clarify this unity, though Locke is not very specific about how this works.

For Locke, essence is what qualities are dependent on and exist in.

Does this new collection of qualities change the essence from “tree” to something new?

In Locke’s view, the essence persists through any change, remaining the same despite changes in the object’s properties.

A third reason Locke seem to be compelled to accept the notion of essence is to explain what unifies ideas that occur at the same time, making them into a single thing, distinct from any other thing.

Essence helps clarify this unity, though Locke is not very specific about how this works.

For Locke, essence is what qualities are dependent on and exist in.

Locke’s ContributionLocke’s ContributionLocke’s view that our knowledge is much more limited

than was previously supposed was shared by other seventeenth- and eighteenth-century thinkers such as Descartes and Hume—even though Locke differs sharply from Descartes about why that knowledge is limited.

For Locke, however, the fact that our knowledge is limited is a philosophical rather than practical matter.

Locke points out that the very fact that we do not take such skeptical doubts about the existence of the external world seriously is a sign of how overwhelmingly probable we feel the existence of the world to be.

Locke’s view that our knowledge is much more limited than was previously supposed was shared by other seventeenth- and eighteenth-century thinkers such as Descartes and Hume—even though Locke differs sharply from Descartes about why that knowledge is limited.

For Locke, however, the fact that our knowledge is limited is a philosophical rather than practical matter.

Locke points out that the very fact that we do not take such skeptical doubts about the existence of the external world seriously is a sign of how overwhelmingly probable we feel the existence of the world to be.

Locke’s ContributionLocke’s ContributionThe overwhelming clarity of the idea of an

external world, and the fact that it is confirmed by everybody except madmen, is important to Locke in and of itself.

Even so, Locke holds that we can never have real knowledge when it comes to natural science.

Rather than encouraging us to stop bothering with science, Locke seems to say instead that we should be aware of its limitations.

The overwhelming clarity of the idea of an external world, and the fact that it is confirmed by everybody except madmen, is important to Locke in and of itself.

Even so, Locke holds that we can never have real knowledge when it comes to natural science.

Rather than encouraging us to stop bothering with science, Locke seems to say instead that we should be aware of its limitations.