Einstein's empirical creed

Max Born, in his Physics in my generation, reports Einstein's empirical creed:

"Concepts which have been proved to be useful in ordering things easily acquire such an authority over us that we forget their human origin and accept them as invariable. Then they become 'necessities of thought','given a priori', etc. The path of scientific progress is then, by such errors, barred for a long time. It is therefore no useless game if we are insisting on analysing current notions and pointing out on what conditions their justification and usefulness depends, especially how they have grown from the data of experience. In this way their exaggerated authority is broken. They are removed, if they cannot properly legitimate themselves; corrected, if their correspondence to the given things was too negligently established; replaced by others, if a new system can be developed that we prefer for good reasons."

quoted in Physics in my generation, Einstein's statistical theories.

Those are the conditions necessary to the evolutionary march of ideas. I also like the comment that ideas are and will always be of human origin, simple, beautiful and the counterpart, inexact. In such, they are formations of the brain to make nature more understandable to our eyes; but they are not nature itself.