It is often in discussion about fringe ideas that the following type of statements are made; "science doesn't know everything" or "everyone used to think the world was flat". These are often presented as bolstering the claims put forward, or attacking my critique of certain suggestions that are (thought to be) physically impossible. I do my best to not dismiss these statements as the appeal to credulity that they are often presented as and see them instead as an expression of the desire to expand knowledge.
When taken seriously we can see that of course science doesn't know everything. It hardly knows anything. But this isn't some secret it is an important aspect. Science is a way of knowing, not a body of knowledge. The body of knowledge that is associated with it is a collection of observations and logical constructions to be drawn upon but are by no means science. Alone on an island with no access to this information you would be able to perform basic science.
The second type, about everyone knowing that the earth was flat etc, always strikes me as funny. The observational data from those that tested their beliefs against the world has shown that it is round for thousands of years. It was only when science was not performed that it was thought otherwise.
At times the use of Einstein to replace Newton is put forth as the suggestion that we don't know anything and whatever fresh bullshit is being put forth is true. I like to take this and use it to fertilize ideas rather than allowing the person to think it fruit. When a new theory overturns old, we do not dismiss the old version. Instead we learn it's limits and the new idea is some form of refinement. At least in the case of scientific ideas. If only one is based on observation and experiment then it may well overturn another showing it to be very wrong.
But even the flat earth model has a use. If you are calculating the physics of a baseball game, or car crash you can treat it as Newtons physics on a flat earth. Quantum effects, relativity, and the curvature of the planet are not going to be needed for getting results. This information becomes relevant if you refine your scale enough or if you expand your view enough.
If we can say anything about the world it's this; We create a gestalt hallucination based on faulty sense data and feedback mechanisms, this is guided by events beyond our control, and thrown together in brains evolved not to grasp the universe in her majesty, but to grasp a stone to kill a rival or a lion. Still, we have developed a system of charting beyond our own individual failings. We can turn this tool upon anything and have used it to rid the world of horrific diseases and shorten the distance around the world to a days travel. We have used it to probe the very stuff of reality and find it stranger than words can describe. That our view is narrow and our comprehension limited is of no doubt, but it grows. There are many things beyond our purview, and many more that we may never come to know that we don't know.