"Mathematics is a language." Josiah Willard Gibbs (America, 1839-1903).

"The limits of my language are the limits of my world." Ludwig Wittgenstein (Austria, 1889-1951).

"I believe that at present the most important method by which a mathematician derives the greatest benefit from his work as an investigator of nature is the systematic classification of quantities". James Clerk Maxwell (Scotland, 1831-1879).