Terry Eagleton probably gets more credit as a writer than he deserves. At any rate, much of what is good in his writing exists in better forms elsewhere.
One example is his statement, often quoted as an example of his wit, that ‘[i]deology, like halitosis, is … what the other person has.’ This is from his book Ideology, published in 1991. It is quoted in various places, for instance (though not quite accurately) at the opening to a chapter in Daniel Dennett’s book Breaking the Spell.
But it is neither particularly witty nor a precise piece of imagery. Part of Eagleton’s point is that everyone or almost everyone has an ideology. But not everyone has halitosis. Halitosis is a medical condition, a pathology, an abnormality. Also there are many forms of ideology and really only one kind of halitosis. Thus the image of halitosis has the opposite connotations to what Eagleton wants.
Here is a far better similar piece of imagery: ‘No one … is conscious of his own ideology, any more than he can smell his own breath.’
This carries all the right connotations. Everyone has, to some degree, an ideology, just as everyone’s breath has, to some degree, an odour. There are different odours, and different people have different reactions to them. Importantly, one is unlikely to notice, or to find offensive, breath that smells like one’s own. At least two pieces of advice follow from this. If you eat garlic, make sure your partner does too. And beware of making too facile a judgment of the effects of ideology upon those you disagree with.
Expressed in this way, the image gives an illustrative explanation of a very important piece of wisdom. And who expressed it this way? Joan Robinson, in her book Economic Philosophy, first published in 1962. I’m not entirely sure Eagleton borrowed from her. I suspect he did, unwittingly of course. At any rate, as far as I can see, she gets far less credit for her use of metaphor than Eagleton gets for his. Yet hers is smart and precise rather than misleading and pointless.
Indeed, her book is generally overlooked, at least by philosophers of economics who lose much in doing so. Perhaps this has to do with her being female and both philosophy and economics being particularly rich breeding environments for implicit bias. But that may be the ideology talking. Pardon me, if so