4.4: Going Beyond the Information Given

The word ‘inference’ is almost synonymous with ‘reasoning’. We draw an inference when we begin with one or more beliefs (our premises) and use them to arrive at a conclusion. We start with a body of information (or perhaps misinformation, or some of each) and arrive at a new piece of information. Suppose that we know that 94% of the people in the critical reasoning class are from Florida, and later we learn that Ramon is in the course. We infer that Ramon is (probably) from Florida. We arrive at this conclusion based on the two earlier pieces of information. Information processing: transforming information in the input into information in the output Bottom-up processing: transmission of information from sensory receptors up to the brain

Many inferences are drawn so quickly and automatically that we don’t even notice them. Consider a quarterback running an option play. As they run along the line, they must read the location and trajectory of the oncoming defensive players. Then, depending on what is seen, they decide whether to pitch the ball or to keep it. A good option quarterback will usually gather and assess the relevant information very quickly and make the right decision in a split second. When we first learn a skill (like riding a bike or skiing or typing) it seems awkward and unnatural. We must rehearse every step in our minds as we struggle to get the hang of things. But as we become more adept, we no longer need to think about each step consciously; indeed, it often becomes difficult to even say what it is that we do (many good touch typists find it difficult to describe the locations of various keys).

There is some very recent evidence that once we acquire a skill, the ability to use it is relocated in a part of the brain that isn’t accessible to consciousness. But the important point here is that many of the skills we acquire involve gathering and assessing information and drawing inferences from it.

Scientists still have much to learn about cognition, but at least this is clear: much inference takes place very rapidly and below the threshold of consciousness. Once we grant this, it won’t seem so odd to think that perception often (perhaps always) involves something very akin to inference. In fact, it is so similar that some scientists think of perception as a special kind of inference.

Figure \(\PageIndex{1}\): Beyond the Information Given

The conclusion of a deductively valid argument doesn’t contain any information that wasn’t already contained (often in a far from obvious way) in the premises. By contrast, the conclusion of an inductively strong argument does contain new information; its conclusion goes beyond the information given in its premises. An inductively strong argument involves a jump, an inductive leap, to new information in a way that a deductively valid argument does not. This explains why it is possible to have an inductively strong argument with true premises but a false conclusion.