The ease with which one can deliberately alter the form of something or invent an insignificant modification to a major science or to a comprehensive theory which someone else has created, or even the impossibility of sticking to the words of the original author when expounding what one has learned not to mention the particular ends which necessitate such repetition in itself for sich introduces that endless multiplicity of alter ations which give the property of others the more or less superficial imprint of being one's own.