Epistemology/What is analysis?

In our everyday speech, we often use very complex or lofty concepts such as "justice" or "knowledge" but when asked "what is justice?" or "what is knowledge?", we might find it hard to give an exact answer. Despite the fact that we presumably know what these words mean (we can use them perfectly fine when we need to!), we seem to only have a fuzzy idea of what they are or how they work. One of the methods that philosophers use to make our understandings of the words we use less fuzzy is called conceptual analysis. Conceptual analysis rests on the idea that we really do already know what these words mean so that we can reliably test a definition or "analysis" against examples to see if it is right. First, we propose an analysis of the concept we're interested in by placing conditions on what counts as falling under that concept. Then, we test this analysis to see if there are any counterexamples which show that it is not quite right. Counterexamples can come in two forms: (1) the analysis may miss a genuine case of the concept which it should have captured or (2) the analysis may include a false case of the concept which it should not have. If we find either of these counterexamples, we need to alter the analysis appropriately to fix the problem.

Individual necessity
In scenario (1), our analysis misses a genuine example that it should have captured. For example, we may try to analyse the concept of a chair by saying that a chair is "an object that is (i) wooden, (ii) has four legs, and (iii) is something that people sit on". When considering this analysis, we might realise that it misses chairs which are made of plastic and chairs which have less than four legs (e.g. see the picture to the right). Here we can see that when our analysis misses a genuine example, it is because it is too strict and contains too many conditions. Some of the conditions in our analysis aren't individually necessary and have to be removed. In the chair example, we see that not all chairs are wooden and they don't all have four legs so these conditions can be removed. Doing this we are left with an analysis saying "a chair is an object that people sit on".

Joint sufficiency
In scenario (2), our analysis includes something which it shouldn't by mistake. For example, consider the analysis of chair that we have left from the last section: "a chair is an object that people sit on". There are many things that people sit on that are not chairs. Horse riders sit on horses while they are racing, Christians sit on church pews on Sundays, and park-goers often sit on benches or even the grass. Here we can see that when our analysis captures something it shouldn't, it is too broad and we need some extra conditions to rule out the false cases. Overall, our conditions are not jointly sufficient to guarantee that a case is a genuine example rather than a false example. We could add the condition that chairs must not be animals but this wouldn't rule out all the false cases we have thought of. Furthermore, simply adding "not [counterexample]" conditions to an analysis seems ad hoc, it rules out the things it should but it also doesn't give us much insight into why those counterexamples don't count or into what truly makes a chair a chair.

Having seen how difficult it is to analyse even the concept of a chair into its necessary and sufficient conditions, it might become clear here why the analysis of knowledge has been a historically debated topic worthy of an entire section of this textbook. Throughout this section, we will explore various analyses of knowledge and test them to see if they have any counterexamples that mean their conditions are not all individually necessary or jointly sufficient to properly define knowledge.