Table of Contents


PART I: Critical Thinking Primer:

This part of the book is a primer for critical thinking skills that you can practice and develop further in Part II: Analysing Philosophical Texts (see below). If you find the texts and exercises in Part II difficult, don’t forget to revisit these posts. They will repay close study many times over!

Post 0: Thinking – it hurts!
Post 1: What is an argument?
Post 2: Hidden premises
Post 3: More about claims & premises
Post 3.1: Assessing arguments
Post 4: Two kinds of argument
Post 5: Validity & Inference
Post 5.1: More on validity
Post 6: Syllogisms
Post 7: Resisting persuasion
Post 7.1: Resisting statistics
Post 7.2: Resisting obscurantism
Post 7.3: Resisting scientism
Post 7.4: Resisting analogies
Post 7.5: Resisting denial
Post 8: Welcome to the solar system

PART II: Analysing Philosophical Texts
This part of the book is for practicing and developing the critical thinking skills you learned in Part I: Critical Thinking Primer (see above). In Part II, you can find a selection of texts that are widely used in undergraduate philosophy programs. However, it is not important whether your course studies these particular texts or not. The texts have been chosen because each presents a different kind of challenge to the critical thinker. By the time we have covered all ten texts, you will have a rounded ability to see problems from various angles. This should equip you with the skills to tackle any text in your course with confidence.

Post 9: Preparing to read
Post 9.1: On meaning and understanding
Post 10: Descartes’ ‘Meditations’
Post 11: Thomas Paine’s ‘The Age of Reason’
Post 12: Aristotle’s ‘Nicomachean Ethics’
Post 13: Friedrich Nietzsche’s ‘The Challenge of Every Great Philosophy’

Post 14: Niccolo Machiavelli’s ‘Of the Civic Principality’
Post 15: Immanuel Kant’s ‘Fundamental Principles of the Metaphysic of Morals’
Post 16: John Locke’s ‘An Essay Concerning the Human Understanding’
Post 17: George Berkeley’s ‘Principles of Human Knowledge’
Post 18: John Stuart Mill’s ‘Utilitarianism’
Post 19: Plato’s ‘Republic’
Post 20: What the texts teach us about critical thinking


17. Berkeley’s ‘Principles of Human Knowledge’

Berkeley is renowned as the father of philosophical idealism. He took great exception to the materialism of Locke and Newton and endeavoured to show how, using their own assumptions, such a view was untenable. He is most famous for the adage esse est percipi (‘to be is to be perceived’).

In this excerpt of twenty concise paragraphs, Berkeley appears to establish such a radical thesis with remarkably little effort. This is in part due to his easy writing style, and in part due to exploiting a number of confused but widely held assumptions of his day. For the modern day critical thinker, Berkeley’s text provides ample material for developing critical thinking skills.

Take, for example, the point made in paragraph 3 of this excerpt, a linguistic analysis concerning the meaning of the term ‘to exist’. Berkeley takes it that when one says ‘A table exists’, the meaning implies that a table is, or can be, perceived by the speaker or some other mind when in its vicinity.

This kind of linguistic argument is a precursor of the sort that became famously associated with the so-called ‘Ordinary Language’ philosophers of the 20th Century, who tried to either establish philosophical conclusions from the way we speak about things, or – as came to be associated with Wittgenstein and his later corpus of work – to show that in fact some purported philosophical problem ‘dissolves’ once we examine how terms are being misused in philosophical contexts by examining their rules for employment in ordinary, or at least semantically uncontroversial, contexts.

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16. Locke’s ‘An Essay Concerning the Human Understanding’

In the ten paragraphs of this excerpt, John Locke presents an excellent example for any critical thinker, setting out the assumptions of his opponents and rebutting each one in turn with logical analysis. Working through his ideas will always pay dividends, not least because many of the issues and arguments he puts forth – in this excerpt and elsewhere – are still being repeated in debates both in and out of philosophy.

In this excerpt, Locke begins his attack on the doctrine of innate ideas. Apparently still misunderstood by Christian critics, Locke’s point turns not on the fact that people fail to follow supposedly innate moral rules, but that such rules and other supposed innate ideas are not seen to be true when their meaning is grasped in the way that sentences such as ‘It is impossible for the same thing to be and not to be’ are. Even these kinds of sentences – the best candidates that innatists could offer in Locke’s time for God-given truths – are not, as Locke argues in the pages following this extract, examples of innate truths provided by God but merely semantic tautologies.

While the question of whether there are any innate ideas or not was certainly not settled by Locke, it did stimulate a century of debate between the opposing camps of rationalists and empiricists (Locke’s view belongs to the latter camp). Kant had sought to resolve that impasse with his ‘Copernican revolution‘, but discussions in the 20th Century by Chomsky and others regarding language use led to something of a revival for the doctrine of innatism.

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15. Kant’s ‘Fundamental Principles of the Metaphysic of Morals’

For the critical thinker, they don’t come much more challenging than Kant, and in this excerpt from his “Fundamental Principles of the Metaphysic of Morals”, you will be faced with a series of challenges that test all that you learned in the Part I: Primer part of this book.

First of all, Kant uses the science of his day – foreshadowing the Darwinian idea of evolution – to ground his argument. Secondly, he attacks the then still fashionable premise of the Enlightenment – that reason is the ultimate guide to happiness – not in order to show that reason is faulty, but rather to show why man stands above nature and mere hedonism. If reason cannot guide us to happiness, Kant concludes, then it is happiness that we must reject, not reason. Aristotle, while searching for the aim of the human being, had – in short – got things the wrong way around.

Kant is a challenge not just because of his complex and often water-tight argumentation but also for his language. Written originally in German, early translations such as this retain a literary and prosaic beauty that require deliberate reading by the modern student. Kant’s texts are highly rewarding so long as each line is read diligently and given enough time to be assimilated.

Many years after Kant, the existentialist philosopher Albert Camus, famously asked ‘Why should I not commit suicide?’ After all, if life has no intrinsic purpose and is nothing more than a sequence of meaningless moments whose aim is the avoidance of pain, no other question could be more pressing. Camus had apparently not read Kant carefully enough, for in this excerpt the answer is clearly given. Unlike Camus, Kant professed a belief in God, but the nub of his answer relies less on religious devotion and more on an understanding of how the faculty of reason – whatever its origin – places a demand of responsibility upon those that possess it.

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14. Machiavelli’s ‘Of the Civic Principality’

The next text is an excerpt from The Prince by Niccolo Machiavelli. He is the best kind of writer for the student of philosophy because his aim throughout is always clarity rather than style. ‘The Prince’ was written for a prince, in the hope that it would secure its author gainful employment as an adviser. It is possibly the longest cover letter in support of a job application in history. Rhetoric and obfuscation never aid the purpose of such a project, and Machiavelli will have known that his reader would have had little patience for complex ideas.

Instead, what Machiavelli does is offer a guide to successful political strategy by means of case history, simple abstraction and logical analysis. His work has stood the test of time, and – if one substitutes for ‘prince’ the notion of ‘president’ or ‘prime minister’ and ‘nobles’ with the plethora of other interested parties who currently wield political power – his advice has as much application today as it did in sixteenth century Italy.

Make notes in the usual way, identifying the main point of each paragraph and writing a 50 word summary (paragraph main ideas are given in the answer key).

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13. Nietzsche’s ‘The Challenge of Every Great Philosophy’

This excerpt from Friedrich Nietzsche provides a different set of challenges from the preceding ones. As was noted earlier, one of the source of difficulties – and, conversely, one of the pleasures – of reading philosophy is the various styles one must deal with. Nietzsche’s style is literary, which makes him eminently readable on the one hand yet frustratingly enigmatic on the other. He deals less in formal argument and more in aphorism, observation and assertion. He often places his own thoughts in the mouths of fictional or historical figures, weaving a complex tale of allegory, allusion, prophecy and psychological insight punctuated with doses of brilliant analysis. Nietzsche’s persuasive power and fame are as much attributable to his artfulness as a writer as they are to his philosophical intellect, and it seems certain that a lesser writer with similar ideas would have made nothing like the same impact.

The text appears perspicuous enough on a first reading, but much may be hidden to the novice reader without careful attention to the smallest of details. Make notes about each paragraph using the reading technique discussed earlier. You will find paragraph main ideas, answers to the questions and a commentary in the answer key.

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12: Aristotle’s ‘Nicomachean Ethics’

Most philosophy courses require students to tackle Aristotle at some point and for good reason: not only does his work cover almost the entire breadth of human interest, but much of what he had to say still informs modern discussions in biology, psychology, ethics, physics, politics and law, not to mention philosophy itself.

Aristotle’s method is unlike that of his predecessors and his work requires a somewhat different approach by the critical thinker. Not only did he make heavy use of observation and classification but he also took care to consider the opinions of both experts and lay people. He was, in this sense, the forerunner of both modern empirical method and academic credibility. This means that the reader must handle a wide range of differing assumptions and examples when reading his work.

Approaching ancient texts always requires some caution. Vocabulary in particular presents a unique challenge: translations from one interpreter to another can be inconsistent, and some terms can only awkwardly be forced into modern parlance.

In this excerpt from Book II of Aristotle’s ‘Nicomachean Ethics’, we will meet Aristotle’s concept of virtue, which is not easily rendered into modern English. A virtue, in Ancient Greek, is often parsed as being ‘an excellence’, but this hardly makes the notion much clearer to the modern reader. The Greek concept of virtue is not, as is our modern English one, solely concerned with moral behaviour. Rather, referring to some thing’s virtue is understood as referring to ‘its best or highest quality’. Thus, Aristotle can make the distinction at the beginning of Chapter 1 between man’s best intellectual qualities and his best moral qualities by use of one and the same word.

The word ‘passions’ is also used with a slightly different meaning to our modern one. It is synonymous with ‘desire’ in the general sense, rather than the ‘intense desire’ of our modern word.

You will find paragraph main ideas, answers to the questions and a commentary in the answer key.


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11: Thomas Paine’s ‘The Age of Reason’

In ‘The Age of Reason’, Thomas Paine offers devastating arguments against the “Christian mythology” that make the rantings of people like Richard Dawkins look infantile in comparison. Paine rejects both organized religion and the bible’s portrayal of a vindictive, vengeful God. Like Aristotle, he argues in favour of deism and rejects any appeal to divine revelation. Rather, the belief in God is a logical conclusion to the question of why anything should exist at all.

In this excerpt from ‘The Age of Reason’, there are twenty-six short paragraphs. Be sure to follow the reading technique as set out earlier. You should get into the habit of making notes while you read, and especially of noting down the main idea of each paragraph.

At first, you will find this slow-going, but after a little practice you will become adept at it, and you will find it saves you an enormous amount of time and thought when you come to writing your essays and revising for exams. Equally, once you’ve made your notes, don’t forget to write a 50-75 word word summary of the text (paragraph main ideas are given in the answer key, the link to which is at the end of the excerpt).

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9.1 On meaning and understanding

Let me tell you a short story about a cat, a mat and a couple of people. We’ll start with Jack.

Jack says: The cat is sitting on the mat.

What Jack says is true. However, Jill’s reply is also true:

Jill says: No it isn’t.

How can Jack and Jill’s utterances both be true? Surely, one of them must be wrong? The simple answer is that Jack is speaking on the telephone, and he is referring to the black cat and the blue mat in his living room. Jill, in her home, is thinking of her white cat, who is sitting on her knee.

Now suppose Jill’s white cat is, coincidentally, sitting on Jill’s green mat. Jack doesn’t know this, when he says, truly

The cat is sitting on the mat.

Jill, who doesn’t even know Jack has a cat, agrees that Jack has spoken truly. However, there is something wrong with Jack and Jill’s agreement. They both agree the statement is true, but the statement has a different meaning for each of them, and in a very important sense, Jack and Jill, while superficially agreeing with each other, are not actually agreeing at all. The agreement is an illusion. They are, in fact, miscommunicating rather than communicating successfully. (The miscommunication would soon become obvious once either of them started adding more details, such as Jill saying, ‘Yes, but I wish it was easier to get all those white hairs out of the mat!’. Jack would be quite confused.)

What has all this got to do with developing our reading skills? When we read a text, we enter into a relationship with the author that is similar to that of Jack and Jill. When an author says

“Intelligence is an inherited ability”

he could be right and he could be wrong at the same time; alternatively, we could think he is right — correctly — but still not understand what he meant. Just as with the cats, it depends on what the author was referring to when he used words like “intelligence’ and ‘inherited ability’, and whether we understand the meaning of those words in the same way.

This is, of course, a general problem about language, meaning and communication. However, in many situations such as face-to-face conversations or textual exchanges, we may have access to the author to find out his or her real intent.

If we realise a miscommunication has occurred (‘What white hairs?’ says Jack), we can ask for clarification from the author. But often, also, we do not have access to the author or to the original intent.

Then we have to rely on other things: background knowledge, experts who know more about the author’s thoughts from other works, our linguistic intuition (in the case of dealing with a foreign language or a translation), and finally — perhaps most importantly — logical coherence. What interpretation of the text makes the best sense, given all that we know?

Some postmodernist thinkers believe that this last consideration is the only one worth attending to. They suggest that even the author’s own intent, which perhaps we can never truly know, cannot help us interpret the best meaning for us in a given situation.

I don’t wish to discuss this view here, though I will note that, in my opinion, it is probably not a coherent position if we try to fully cash it out. However, whatever the truth about that, the fact is that there is often more than one possible interpretation of a text. Some interpretations make more sense than others, some may be equally valid, and some may make no sense at all (they may lack logical coherence with other ideas in the text, may misunderstand vocabulary, may not cohere with other things known about the author or topic).

This is why we say there is sometimes more than one right answer, that some answers may be just wrong, and always that we need to discuss and share our interpretations.
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10. Descartes’ ‘Meditations’

The twelve paragraphs in our first excerpt are from one of the most famous and influential texts ever published in Western Philosophy. They belong to Rene Descartes ‘Meditations on First Philosophy’, which is a standard reading for philosophy students all over the world. Descartes writes in a fluent and narrative style, but what makes it difficult for modern readers is not just the occasional low-frequency vocabulary but also the old-fashioned grammatical structures.

Set aside around 50 minutes to read the text and to make your notes. As you read, remember to follow the steps as set out in the reading technique. After having read the text and made your notes, try to answer the questions at the end of the excerpt.

Answers to the questions, paragraph notes, and a commentary are provided on the answer page, the link to which is at the end of the excerpt.

Enjoy! 🙂

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