Many of our utterances carry much more than their literal meaning.

Suppose I am hosting a dinner party at 7pm. At 4pm, one of my guests texts me, “I’m free from 6pm”. From that, I will understand, “I’m free from 6pm and I’d like to arrive early if that’s OK?”

As the evening progresses, another of the guests says something horribly rude. I respond with, “So, what did you think about the fish?” From this, my guest ought to understand that he has overstepped the mark.

As a writer, I am acutely aware that I am conveying much more than the words on the page. As a psychiatrist, I am acutely aware that my patients are disclosing much more than the face value of their words.

So, how do our words and sentences work so hard?

The British philosopher Paul Grice (d. 1988) attempted to answer this question by his theory of implicature.

Grice distinguished conventional implicatures, inherent in certain words such as “but”, “therefore”, and “indeed”, from conversational implicatures, which arise from a sort of game-playing, and rule-observing, between speakers.

Let me give you an example of each.

If I say, “She was poor but honest”, I am, by the simple use of the word “but”, also conveying or betraying a certain prejudice that poor people are generally dishonest.

A few hours before my dinner party, I bump into a friend while stepping out of a bakery with three loaves under my arm. My friend asks, “How are you?” To which I respond, “My first dinner party tonight!” By which she understands, “I’m excited because tonight I’m throwing a dinner party for the first time since the U.K. coronavirus lockdown.”

With conversational implicatures, our utterances can take on added meanings, or different meanings, according to the situation or context in which they are uttered.

When we speak to our partner in a crowded place, they are able to derive much more meaning from what we have said than the strangers who are also in earshot, in part because they are leaning upon background information that is privy only to the both of us. Our partner is capturing not only our words, but also how they fit in, and work with, push against, or wrap around, the world that we share.

More interesting, I think, is that non-literal meaning can also be created by pushing against certain general and deeply ingrained principles of communication and co-operation. In particular, meaningful conversation can only take place on the assumption that the speakers are, at least on an epistemic level, cooperating with one another.

Grice divided this so-called cooperative principle into four maxims of conversation:

1. Maxim of quality: That utterances ought to be sincere, justified, and truthful.
2. Maxim of quantity: That the right amount of information ought to be provided.
3. Maxim of relevance: That the information provided is in some way pertinent.
4. Maxim of manner: That the information provided is as clear and unambiguous as possible.

Whenever one or more of these maxims appears to have been flouted, we reflexively assume that the speaker must somehow have observed the maxims and start searching for a likely non-literal meaning.

In other words, implicature arises when the Gricean maxims are flouted, or would have been flouted had it not been for the implicature. Category examples of floutings that, by implicature, are not true floutings include irony (maxim of quality), metaphor (maxim of relevance), and euphemism (maxim of manner).

But, of course, the maxims are not invariably observed. Politicians in particular often flout the maxims, for instance, by answering a different question to the one asked, or providing a much longer answer when a simple “yes” or “no” would have sufficed, or been preferable. In such cases, most of the interviewer’s interjections are, in effect, attempts to return the politician to the maxims.

Conversational implicatures serve a number of important functions such as: increasing the efficiency of communication; making communication more lively, varied, and humorous; and introducing ambiguity or restraint to avoid being ostracized or otherwise penalized for speaking hard truths.

But this slipperiness, this malleability, also gives rise to a number of ethical and legal problems—which is why legal contracts, witness statements, and the like are expected or even required to be as concrete and literal as possible.

More fundamentally, while we can be held responsible for what we say, to what extent can we be held responsible for what we implicate?

Today, many politicians resort to implicature, on Twitter and elsewhere, to get away with saying the unsayable.

In the words of the Persian poet Hafiz, “The words you speak become the house you live in.”