Mach:

Let’s just imagine that we lose all our personal property. In that case we would recall that apart from ourselves there are still simple people, who in such a situation would be vastly superior to us in experience and skills. But what is science itself? It’s simply the most economical summary of such experiences made by humankind!

Einstein:

But your argument fails to recognize the free constructive element in the formation of concepts. All science is the refinement of everyday thought. No empirical methods can be created without speculative concept constructions; and there is no speculative thought whose concepts do not betray the empirical material to which they owe their origin.