Palgrave foundations series

by Bryan Greetham

Philosophical terms

Philosophical terms are not always clear, and can cause a great deal of confusion. In this section, you will find extended definitions of the terms that are most troublesome in the study of philosophy, and allow you to really get to grips with the subject.

Contrary, converse and opposite

In Chapter 3 of Philosophy we examined ‘obversion’ and ‘conversion’. Although simple ideas in themselves, they can be confused with other ideas that are similar. In particular, the converse of something is easily confused with the ‘opposite’ or the ‘contrary’ of something.
1. Converse

Having read Chapter 3 you will know what it is to talk about the converse of something. It is a statement in which the subject and predicate have changed places. For example, the converse of the statement,

‘All men are mortal’
‘All mortal beings are men.’

2. Opposite

In contrast, the opposite of the same statement,

‘All men are mortal’
‘No men are mortal.’

With opposites there is no common ground: ‘mortal’ and ‘immortal’ are contradictories. The opposite of the statement ‘This is white’ is ‘This is black.’ So, opposites must comply with two fundamental logical laws:

1. The Law of Contradiction:
A is not not-A

In other words, something or a person cannot be in the same sense A and not-A.

2. The Law of the Excluded Middle:
Either A or not-A

In other words, there is no middle ground – the two terms are mutually exclusive.

3. Contrary

Contraries, however, do not exclude the opposite, but include it as their most extreme form. Contraries represent the two extremes of a continuous series of variations. So, where the statement, ‘This is white’, has only one opposite – ‘This is black’ – it has many contraries including the following:
  • ‘This is not white’
  • ‘This is coloured’
  • ‘This is grey’
  • ‘This is dirty’
as well as,
  • ‘This is black.’
You can no doubt think of many of your own examples, like young and old, sane and insane, civilised and uncivilised, even man and woman. There is a real difference between each term, but we cannot say when a thing or person stops being one and becomes the other. There is no sharp dividing line, just a series of imperceptible degrees.

Even so we must know from what point of view we’re using these terms and what facts we’re taking into account as a result. From one point of view the terms man and woman are contraries, rather than opposites. If you were talking about the different temperaments of people, some being intensely rational, which we are inclined to associate with men, and some being more emotional and intuitive, which we associate with women, most likely you would be talking in terms of contraries, that some people have more of one type of temperament than the other. In recent years with the increasing popularity of some forms of psychotherapy we have become more used to talking about people having their male and female sides. Men are often told that the only way in which they can deal with their personality problems is to ‘get in touch with their female side’. However, if you were to adopt a different point of view and, say, talk about the physical differences between men and women, you would, of course, be talking in terms of opposites.

Given this I’m sure you can see how problems and confusions arise. In an argument one person can succeed by forcing the other person to accept a precise definition where none exists. In other words, you may be forced to apply the Law of Contradiction and the Law of the Excluded Middle in cases where only contraries are in question. For example, you may be engaged in an argument using the contraries sane and insane, where the other person uses them as opposites and insists that you must be clear about the terms you are using, so you can identify the point where one becomes the other. Knowing how important it is for you to define your terms clearly you are easily encouraged to begin to use the two terms as opposites, when it is more appropriate to use them as contraries.

To make the point perfectly clear I have written below what you might think is a typical argument between two people where one person has just been fined for reckless driving. As you can see, although there is a lot of pressure in conversations like these to define your terms precisely, so you can make clear distinctions between them, it is reasonable to hold your ground when what you are talking about are contraries, rather than opposites. Still, that’s not to say that this should excuse our deliberate vacillation. For practical purposes we may still have to make a decision even though we are confronted with contrary notions. If we were given the job of drawing up speed limits for a town we would have to make our decision to fix them at some point where we believe driving in excess of this is likely to be dangerous or pose unacceptable risks to all other road users.

Indeed we are all asked to make these sorts of decisions whenever there is an election. Each party will try to convince us that the other parties’ policies are unwise and dangerous to our well-being, while their own policies will result in a higher standard of living and greater contentment. But we know that it is more complex than this. Each party’s policies are likely to be as good or bad as each other. But this doesn’t mean we are free to shrug our shoulders and walk away without making a decision.


1. Give the opposite and 3 contraries of the following:

a) This steak is raw.
b) It is cold today.
c) That child is obese.

2. What are the converse forms of the following?

a) Some accountants are businessmen.
b) A is bigger than B.
c) Many politicians are lawyers.