Critical Reasoning: A Romp through the Foothills of Logic (Online)


Reasoning enables us to acquire knowledge, to persuade others and to evaluate their arguments. But only if we reason well. We shall be learning how to recognise, evaluate, construct and analyse arguments, and how to recognise common fallacies (bad arguments that look like good arguments). This will give you confidence in your ability to reason well.

Reasoning is central to the life of a human being. Without it we would be restricted to learning through our senses and immediate experiences. Reasoning can take us, literally, to the moon and back. Reasoning enables us to theorise about our world, to persuade others of our theories and to evaluate theirs. But reasoning can do this only if we do it well. Bad reasoning takes us nowhere. In this course we shall be looking at how to recognise and evaluate arguments, how to construct and analyse arguments and how to recognise common fallacies (bad arguments that look like good arguments). By the end of this course you should be more confident about your everyday reasoning, your ability to present a good case to others, and your ability to distinguish a good argument from a bad one.

Listen to Marianne Talbot talking about the course:

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Programme details

1. The Nature of Argument
In this unit we' learn how to recognize arguments and distinguish them from other sets of sentences, and from assertions, especially conditional assertions.

  • Defining argument
  • The principle of charity
  • Personality types
  • Asking for explanations
  • Background: declarative sentences
  • Truth values and truth conditions
  • Simple and complex sentences
  • Arguments as sets of sentences

2. Analysing Arguments
In this unit we' look at how to analyse arguments and set them out 'logic-book style'. This makes it much easier to see the structure of the argument (which in turn makes it much easier to evaluate the argument).

  • Ambiguity: what it is and why it is important
  • Types of ambiguity
  • The importance of clarity
  • Identifying premises and conclusions
  • Setting out arguments logic-book style
  • Making terms consistent
  • Eliminating irrelevancies
  • Explicating suppressed premises
  • Suppressed premises

3. Deduction and Induction
This is the unit in which we learn how to distinguish deductive arguments from inductive arguments. Deduction and induction are two quite different types of argument. All arguments fall into one category or the other. The two types of argument are evaluated quite differently.

  • Two types of 'following from'
  • Logical and empirical possibility: epistemology and metaphysics
  • Deductive arguments are good or bad
  • Inductive arguments are strong or weak
  • Conclusivity, monotonicity and certainty
  • A priori versus a posteriori
  • Induction and necessity of empirical experience and observation
  • Distinguishing deductive arguments from inductive arguments

4. Induction, Popper and the Paradoxes of Confirmation
In this unit we will be stepping back from critical reasoning to consider the philosophy of critical reasoning. In particular we will be considering the nature of induction and some problems endemic to inductive reasoning.

  • David Hume and the first problem of induction
  • The principle of the uniformity of nature
  • Justifying the PUN
  • The rationality of induction
  • Karl Popper and the rejection of induction
  • A model of the scientific method
  • Is induction less valuable than deduction?
  • Concluding comments and questions
  • First assignment

5. Types Of Induction
Having got to grips with the problems endemic to inductive reasoning we shall now consider the different types of inductive reasoning, and look at how to evaluate them.

  • Background
  • Inductive generalisations
  • Evaluating inductive generalisations
  • Causal generalisations
  • Evaluating causal generalisations
  • Abductive arguments
  • Evaluating abductive arguments
  • Analogies and evaluating analogies
  • Arguments from authority and evaluating arguments from authority

6. Deduction, Validity And Truth
In this unit we will consider how to evaluate deductive arguments. We will start by reflecting on the notions of validity, entailment and truth. Then we wi'll look at the process by which all deductive arguments are evaluated.

  • Deduction
  • Validity, truth and soundness
  • Validity and knowledge
  • Circularity
  • The paradoxes of entailment
  • Evaluating deductive arguments
  • Testing for consistency
  • Testing for consistency with Venn diagrams
  • Testing for consistency with semi-formalisation
  • (In)consistency and (in)validity

7. The Rudiments, Purpose and Limits of Formalisation
In this unit and the next we shall be looking at the rudiments of formalisation. Why do logicians use symbols? How do they help? In unit seven we shall ourselves learn how to formalise simple arguments.

  • The purpose of propositional logic
  • The limits of propositional logic
  • Constructing interpretations
  • Sentence functors and truth functors
  • Truth functor symbols
  • Problems with ‘not’ and ‘~’
  • Problems with ‘and’ and ‘&’
  • Problems with ‘or’ and ‘∨’
  • Problems with ‘If/then’ and ‘→’
  • Problems with ‘iff’ and ‘↔’
  • Expressing English sentences in truth functor symbols
  • Sequents

8. The Rules of Propositional Logic
Having learned in the last unit how to formalize simple arguments we shall now learn how to apply a set of mechanical rules by which to test these formalized arguments.

  • Testing semantic sequents
  • Counterexamples
  • Testing syntactic sequents
  • Concluding comments and questions
  • Second assignment

9. Fallacies
The last two units have been tough. This unit will be a bit of relaxation. In this unit we wi'll learn about fallacies. These are bad arguments that look like, and can easily be mistaken for, good arguments. You' will do some research of your own into particular types of fallacy.

  • Fallacies
  • Formal fallacies
  • Informal fallacies
  • Reflections on the course so far

10. Analysing Complex Arguments
In this, our final unit, you wi'll be set the task of analyzing a complex argument. Half of you will analyse a complex inductive argument, the other half a complex deductive argument.

  • Activity one: Analysing and evaluating arguments
  • Activity two: Checking the work of other students
  • Activity three: Self-assessment
  • Activity four: The Glossary
  • Activity five: Summing up your thoughts
  • What next?


We strongly recommend that you try to find a little time each week to engage in the online conversations (at times that are convenient to you) as the forums are an integral, and very rewarding, part of the course and the online learning experience.

Digital Certification

Credit Application Transfer Scheme (CATS) points 

To earn credit (CATS points) for your course you will need to register and pay an additional £10 fee for each course you enrol on. You can do this by ticking the relevant box at the bottom of the enrolment form or when enrolling online. If you do not register when you enrol, you have up until the course start date to register and pay the £10 fee. 

See more information on CATS point

Coursework is an integral part of all online courses and everyone enrolled will be expected to do coursework, but only those who have registered for credit will be awarded CATS points for completing work at the required standard. If you are enrolled on the Certificate of Higher Education, you need to indicate this on the enrolment form but there is no additional registration fee. 


Digital credentials

All students who pass their final assignment, whether registered for credit or not, will be eligible for a digital Certificate of Completion. Upon successful completion, you will receive a link to download a University of Oxford digital certificate. Information on how to access this digital certificate will be emailed to you after the end of the course. The certificate will show your name, the course title and the dates of the course you attended. You will be able to download your certificate or share it on social media if you choose to do so. 

Please note that assignments are not graded but are marked either pass or fail. 


Description Costs
Course Fee £350.00
Take this course for CATS points £10.00


Dr Julia Weckend

Julia has taught philosophy at the Universities of Reading and Southampton before joining Oxford University’s Department for Continuing Education. She regularly teaches weekly classes as well as courses for Oxford University Summer School for Adults and Oxford Experience. Her academic research focuses on issues in metaphysics and epistemology. She has published papers and edited two volumes in the history of philosophy, and she is a co-author of the Historical Dictionary of Leibniz’s Philosophy (2023).

Course aims

  • Introduce participants to the nature of arguments and the different types of arguments.
  • Help participants learn how to evaluate arguments of the different types.
  • Encourage participants to acquire the 'language of logic'.
  • Enhance participants' confidence in everyday reasoning and argument.

Course objectives

  • Understand what an argument is
  • Recognise arguments
  • Analyse arguments
  • Distinguish deductive arguments from inductive arguments
  • Evaluate inductive and deductive arguments
  • Understand formal and informal fallacies
  • Understand the rudiments of formalisation
  • Apply the rules of propositional logic

Teaching methods

  • Guided reading of texts
  • Group discussions of particular issues
  • Questions to be answered in personal folders
  • Debating from positions given rather than from personal belief (to hone skills of debate)

Learning outcomes

By the end of this course students will be expected to understand:

  • How to recognise arguments, distinguish them from conditional sentences and sets of sentences that are not arguments, and set them out 'logic-book-style'.
  • Understand the difference between deduction and induction, and the different types of each argument-type and how they are distinguished from each other.
  • Evaluate arguments by testing them for validity or inductive strength, and checking the truth of their premises.
  • Understand and recognise common fallacies.

By the end of this course students will have gained the following skills:

  • Confidence in everyday reasoning and argument.
  • The ability to distinguish deduction and induction and recognise the strengths and weaknesses of each.
  • The skills involved in analysing arguments and setting them out logic-book-style.
  • An understanding of how to evaluate arguments of different types.

Assessment methods

You will be set two pieces of work for the course. The first of 500 words is due halfway through your course. This does not count towards your final outcome but preparing for it, and the feedback you are given, will help you prepare for your assessed piece of work of 1,500 words due at the end of the course. The assessed work is marked pass or fail.

English Language Requirements

We do not insist that applicants hold an English language certification, but warn that they may be at a disadvantage if their language skills are not of a comparable level to those qualifications listed on our website. If you are confident in your proficiency, please feel free to enrol. For more information regarding English language requirements please follow this link:


Please use the 'Book' or 'Apply' button on this page. Alternatively, please complete an Enrolment form for short courses | Oxford University Department for Continuing Education

Level and demands

FHEQ level 4, 10 weeks, approx 10 hours per week, therefore a total of about 100 study hours.

IT requirements

This course is delivered online; to participate you must to be familiar with using a computer for purposes such as sending email and searching the Internet. You will also need regular access to the Internet and a computer meeting our recommended minimum computer specification.