If somebody describes herself as "not tall, not short, not fat, not thin", she is saying that she is of average height and weight. While it may seem cumbersome, this sort of indirect method of conveying information by elimination can sometimes be most efficient.
Bridge bidding systems, for instance, use "exclusion principles". There is a limited, though very large, number of possible bridge hands. Bidding conveys information about card distribution. It is often more efficient for a bidder to state that certain distributions are not held. That enables the partner to get a good idea of what the bidder does hold.
Exclusion is also an interesting way to analyse political statements. Narendra Modi, for instance, has never expressed any regret for what happened in 2002, and the lack of even a single statement to that effect has probably affected his career more than all the things that Mr Modi has actively said and done since Godhra.
Rahul Gandhi's recent speech at the Confederation of Indian Industry meet could be considered a mine of information because there were so many things left unsaid. Mr Gandhi was directly addressing the shrewdest, hardest-headed and most successful people in India; indirectly, he was speaking to a global audience. He must have known that people would parse his every "hum" and every "haw".
The forum was ideal for laying out the details of concrete policies designed to foster faster and more inclusive growth. Mr Gandhi did not, however, choose to speak in concrete terms, or about concrete measures.
He did not mention the goods and services tax (GST). He did not touch upon the need for accelerating the passage of crucial economic legislation, stuck in Parliament for years. He did not acknowledge that the government must speed up clearance processes not only to enable faster infrastructure creation in future but to ensure that lakhs of crores do not remain stuck in stalled projects. He did not discuss the ways in which regulatory barriers to private sector investments in education could be removed.
Instead, he spoke - sometimes in wildly mixed metaphors - about the blindingly obvious. India has a young dynamic population - everybody in the audience is part of that population and most are targeting it in their business plans. Educational standards are woeful - yes, but nobody in the private sector can do much about it while the barriers to investing in education are as high as currently. India needs better infrastructure - folks in that audience have invested lakhs of crores to improve it and run into bottlenecks.
There were some anecdotes about young urban migrants and their aggressively optimistic attitude. The plural of anecdote is not data. But it is true that some 15-20 million young rural Indians move every year to the cities. Officially, about 30 per cent of Indians are urban and they generate over 70 per cent of the gross domestic product.
The migrant Mr Gandhi mentioned, "Girish" from Gorakhpur, may or may not be an official resident of Mumbai. It is irrelevant that he probably lives in Mumbai for 11 months of the year. His voter ID may describe him as a Gorakhpur resident.
The UID programme makes sweeping promises about rectifying this sort of information gap, while being less than clear on the subject of data protection. Mr Gandhi did not clarify what, if anything, is being done either to improve data protection or to speed up UID enrolment.
The only concrete promise he made was that the Congress would provide a rights-based framework. A "guy" (to use Mr Gandhi's favoured description) named Ambedkar already did that, more than 60 years ago. What is missing is the justice system or political will to deliver those rights that exist on paper, and nothing was said about that.
In Mr Modi's case, his lack of any expression of remorse about the 2002 riots has led people to infer that he actually feels no remorse. What, if anything, can one infer from the lack of mention of any concrete policy initiatives by Mr Gandhi? Some things are better left unsaid.