Knowledge can become out of date, because what we thought to know appeared not to be true. The case of Galileo that I described two weeks ago is an instance of this: the sun does not turn around the earth, as people thought in his days, but it is the other way round, as Galileo showed. So what we thought to know has never been the case. Actually, it has never been knowledge: it was false knowledge. But is it so that all supposed knowledge that later appeared to be false knowledge always has been false knowledge? Take the so-called bystander effect, the phenomenon that most persons do not help a victim in an emergency situation (for instance a drowning person), when other people are present, while they would help, if they were there alone. However, now I read in an article that it has become difficult to replicate the bystander effect in an experimental setting. Apparently people have changed – maybe because the phenomenon got much attention in the media and in publications – and the bystander effect does no longer exist: people do help now in emergency situations, even when they are in a group. What once was true has now become false and has been replaced by new knowledge.
On the face of it, it seems here that a piece of knowledge simply has become out of date and has been replaced because we know better now. However, there is an important difference with the Galileo case. There the original idea that the sun turns around the earth has always been false, but the bearers of this supposed knowledge were not acquainted with this. However, the bystander effect has not become out of date because it never has been true, for once it was. It has become superseded because reality has changed. This is typical for the social sciences: people get knowledge of certain social facts, which are true at the moment they hear about it. However, for one reason or another, people are not satisfied with the facts and they change them. Then old knowledge becomes the foundation of new knowledge instead of being falsified. By the way, it can also happen that what once was false is made true: a teacher undeservedly thinks that some students in his class are better than other students and just because of his – often unconscious – behaviour the allegedly better students also become better, as psychological research has shown: false knowledge has turned into true knowledge. And in fact, the reversal of the bystander effect is also a case in point: the false knowledge that people tend to help in emergency situations even in case others are present, has become true when people became conscious of their behaviour.
This interpretative effect (called “double hermeneutics”) does not exist in the natural sciences. However, also there it can happen that knowledge becomes outdated and has to be replaced by new knowledge without being falsified. Old medical knowledge is often replaced by new knowledge, not because it has been falsified, but because now we know better. But in a certain sense the medical science is a social science. The latter is not the case for biology and for the biological world, for instance. Nature is in continuous development and what once was true about it, is not valid anymore many years or ages later. Even if our knowledge isn’t true, it needn’t be false. There are many ways that it can appear to be wrong.
When we know something, or at least think so, do we really know it then? Can it be that we on some occasions know a thing and on other occasions we do not know it, even though we haven’t forgotten it and can tell exactly what it is that we are supposed to know? When browsing on the Internet, I found this interesting case by Keith DeRose, which I quote from Nestor Ángel Pinillos “Some Recent Work in Experimental Epistemology” (Philosophy Compass 6/10 (2011): 679):
 My wife and I are driving home on a Friday afternoon. We plan to stop at the bank on the way home to deposit our paychecks. But as we drive past the bank, we notice that the lines inside are very long, as they often are on Friday afternoons. Although we generally like to deposit our paychecks as soon as possible, it is not especially important in this case that they be deposited right away, so I suggest that we drive straight home and deposit our paychecks on Saturday morning. My wife says, “Maybe the bank won’t be open tomorrow. Lots of banks are closed on Saturdays.” I reply, “No, I know it’ll be open. I was just there two weeks ago on Saturday. It’s open until noon.”
 My wife and I drive past the bank on a Friday afternoon, as in , and notice the long lines. I again suggest that we deposit our paychecks on Saturday morning, explaining that I was at the bank on Saturday morning only two weeks ago and discovered that it was open until noon. But in this case, we have just written a very large and very important check. If our paychecks are not deposited into our checking account before Monday morning, the important check we wrote will bounce, leaving us in a very bad situation. And, of course, the bank is not open on Sunday. My wife reminds me of these facts. She then says, “Banks do change their hours. Do you know the bank will be open tomorrow?” Remaining as confident as I was before that the bank will be open then, still, I reply, “Well, no. I’d better go in and make sure.”
The first case is clear: I know that the bank is open on Saturday morning and I behave like that. But how about the second case? If I am sure and know that the bank is open on Saturday morning, there is no need to check it. However, although I am confident to know it, nevertheless I check it. But there can be only reason to check whether the bank is open, if I do not know it or when I am not sure enough about it so that I can say “I know it”. Pinillos discusses then two possibilities: either knowledge is dependent on the context or, although knowledge as such is true, it is sensitive to stakes, i.e. “the idea that whether an agent who believes P also knows P may depend on the practical costs (for that agent) of being wrong about P: when the stakes are high, the epistemic standards for attaining knowledge may be higher.”(676) Pinillos rejects the first possibility. However, I think that there is at least one other possibility, namely that there are degrees of knowledge, an alternative that Pinillos does not discuss. Also then, just as Pinillos says, whether we are going to check our knowledge depends on what the consequences are when we are wrong. But we don’t check when we are for 100% sure. If that were so, we should have to continue checking and checking after each check, for the consequences in case we are wrong haven’t changed after each check. So why would we stop checking? But after the first one our knowledge has increased and we feel sure and that’s why we stop and say: we know it.
I do not know whether you are acquainted with what is happening in the academic worlds in other countries, but recently in the Netherlands social psychology professor Diederik Stapel was dismissed because he had fabricated research data; not only once but so often that his university decided to report it to the police. In Germany, defense minister Karl-Theodor zu Gutenberg had to resign because it came out that his PhD thesis was full of plagiarisms. Since then more such cases have been discovered both in Germany and in the Netherlands. So, inside and outside our ivory tower of science and the humanities not everybody appears to be as original as s/he pretends.
I do not think that I am original in most of my blogs here, but I do not pretend to be so and at least I mention my sources, as every reader can check, and lack of originality is not a crime. But when I considered my recent blogs on knowledge again today, I had to think of the case of this Dutch ex-Prof. Stapel. Let’s suppose that looking for inspiration for my blogs I read an article by Stapel and, since his falsifications had not yet come to light, I had good reasons to think that the research in the article was real and that the data were correct. Also the argumentation in the article was okay, so that I could endorse his conclusion that A was the case. Therefore, given my definition of knowledge as methodically justified interpreted belief (see my blog dated Nov. 14, 2011), one could say that I knew then that A was the case. But, in view of what we know now about Stapel, can we still say that I then knew it? I think so, for then the conclusion was methodologically justified for me, and for many other people too, although not for ex-Prof. Stapel. However, now it is no knowledge any longer. Does this now mean that afterwards I have to change the idea that then I knew it?
One can defend that the “knowledge” in Stapel’s article has never been any knowledge at all, but in a certain sense what happens here is not so different from what normally happens in science, apart from that normally knowledge is not fabricated. For instance, we have an idea about something in reality, like that on average poplars are higher than oaks. We gather data in order to test the idea, for example by measuring 100 mature poplars and 100 mature oaks around here where I live and comparing the average lengths of both. Then we can say that we know now that on average poplars are higher than oaks. But usually things are often not as simple as that. In the days of Galileo most people thought that the sun turned around the earth, but Galileo showed that it was the other way around. So, did we get a change in knowledge? However, before Galileo people had good and sincere reasons to think that they knew that the sun turned around the earth, and this knowledge hadn’t been fabricated, so if you asked someone what s/he knew about the earth and the sun, you got the answer “the sun turns around the earth”. And today we are in the same situation: We think that we know a lot and probably we do, but for every piece of knowledge it is quite well possible that sooner or later someone will say: well, I developed a new research method which is better than the old ones (just as Galileo used a telescope for studying the sky, which was new in his days) and I have applied it and my conclusions are different. The upshot is: fabricated knowledge is false, it’s true (unless by chance the fabrication happens to correspond to reality), but it is not so that what we sincerely and in a methodically justified way think to know is true, even not for us, as the Galileo case shows. Only the chance it is is bigger. And to enhance this chance, that’s what science and the humanities are about.