"Natural science is not conceivable without a recognition of the mechanical element in nature. [...] Why can there be no natural science without this mechanism? The answer is, that without mechanics there can be no standards which are constantly valid and calculable. Without mechanical laws, that exactitude could not be achieved which in itself is nothing but the mechanical certainty that identical causes always produce identical effects. Thus we are justified in calling the natural scientist a mechanic who deserves scientific respect only in so far as in his thinking he retraces the mechanism of nature."