but I'm curious what you mean by 'fundamental knowledge' [maybe an example].
Well, more 'fundamental' in that in philosophy one is dealing with the overall embedded nature of something (e.g., quantum physics, chemistry, art, language, cognitive abilities, etc) versus the study of something. Don't get me wrong, there is a continuum that perhaps exists between science and philosophy, or between law and philosophy, or between computer science and philosophy, etc. However, philosophy is generally looked upon in setting up first principles, guiding principles, organizing principles, etc, in order to fine-tune one's study of a particular discipline.
An example that immediately comes to mind that you might be very knowledgeable about is the positivist influence that Ernst Mach had on the early Einstein (the later Einstein moved away from extreme positivist notions). Mach viewed the concept of absolute time with distain and saw it as a metaphysical concept having no room for entertainment in physical science. He also expressed, if I remember right, a similar distain for the 'ether' concept since this too did not jive with his positivist views. Although positivism finally bit the dust in the 60's, it had a huge impact on science in many different facets. What matters is not so much that positivism was ill-equipped to handle the challenges put before it, but rather that a philosophy can make one look at the foundational issues circulating around one's theories, and thereby make new and captivating theories by changing one's philosophical perspective. If there was a clear advantage that Einstein had over his older peers at the time, it was this.
Another thing I'm curious about is what would be the definition of 'true' and 'approximately true' in a philosophical sense. In a scientific sense true could be that a theiry is experimentally testable and every test has verified the prediction of the theory [repeatable]. But in science nothing is perfect because an error bar will always exist which [could be interpreted] will make repeatable experimental results approximately true.
There's a lot of controversy here. I think you might remember that I sat in a classroom setting given by well-known physicist from Chicago - an excellent physicist to say the least. This physicist's perspective when questioned on this topic is that physics provides approximate truths of the universe. Each succeeding theory is generally more approximately true than the previous theories, and the ones prior are generally engulfed by the later theories. Generally speaking, the earlier theories are specific cases of the latter theories. This, I think, is to say the least, a very popular view in physics. One of the philosophers in that session bit his tongue, but obviously there was a lot of room for disagreement as to the nature of scientific truth.
There are also many problems in rejecting the argument of 'true' or 'approximate truth', and I personally find myself somewhat in the middle in this position. Actually, I think Hilary Putnam's internal realism is very close to the best position, although Putnam is known for changing his perspective frequently, so fixing his position on such matters is rather tough sometimes. His latest position is that truth exists, it is just that it is impossible to conceptualize independently of our conceptual schemes. That is, particulars can be 'true', but the universals are conceptualizations which are relative to one's conceptual schemes. For example, if someone throws a chair so that it hits the wall, the event happened. Someone actually threw a chair and hit the wall. However, try as you might, you cannot describe this event in some mind independent manner. Things like 'chairs', 'walls', 'throw', 'against', etc, are all based on a vocabulary that is internal to the observer. The internal vocabulary is part of a conceptual viewpoint that includes concepts (chairs, walls, throw, etc) that all could be described differently by someone who has no such conceptual ontology (i.e., someone could describe the event in a manner that the words 'chairs', 'walls', etc, were not even recognized as objects).
In any case, I think the operative difference between science and philosophy is that science is concerned with the phrase 'for all practical purposes', and whereas philosophy is not satisfied with this phrase since it is generally not an explanation or definition, but rather a means by which to avoid the philosophical issues. Science, though, works well with that phrase (even when not overtly stated).