“Science should not be likened to a bound hard-cover volume, a collection of unchallengeable, incontrovertible truths. It is more like a loose-leaf folder in which our latest insights into nature, into aspects of ourselves and the accumulated wisdom of past learning are stored.”
The implication: science is more like a soft-cover book. A better analogy would be that science has the features of a loose-leaf file which is appropriately date stamped on every page. Its pages can be removed — but not trivially discarded. Continuity is an important factor in understanding!
What I therefore reject is the notion that a record of what we see has especial epistemic validity. Rather, it is a moveable decision that a “claim of particulars ” has been registered; may be only one of an evolving series. Such a claim is in a position to be challenged, and can continue to being challenged for ever and a day. It is a falsifiable hypothesis which could be overturned by a single negative instance. It cannot be reinstated except by re-writing the “terms of particulars”, as when we change the claim “all swans are white” and replace it with “except those (many) which originated in Australasia”.
“Seeing” here refers to a preferred method of personally checking the status of our claim. Reading a dial, or confirming by noting the change of a beep emitted regularly by an auditory monitor, i.e. hearing, is an alternative method. It is not seeing — the visual act — that leads to believing, but it is the testing of a hypothesis which is critical, no matter how done.
There are many other things which could be done to falsify a hypothesis, although we often let some position die through neglect and then no longer defend it. Hypotheses can become trivialized, and lose their interest and sway over us. For example, a dark, black area in the sky is not “empty space” to an astronomer. He may only see black areas — as do others — but these are not necessarily signs of emptiness! The microbiologists is in a comparable position: he may not see anything — but may add that this may be due to the weakness of the current microscope, then get another or invent a new one.
But what is at peril is the idea that belief is based on experience and furthermore that experience does not lie but is sacrosanct. Experience — note — is our way of expressing the idea that our specific claims have risen beyond reasonable doubt. It is however itself a claim, has to be viewed as such and therefore what we see can be doubted.
Nota bene: There is no free ride to certainty. Each of us has to learn how to maintain doubt during our most perilous moments.