As quoted in Mathematics, Education and Philosophy: An International Perspective (1994) by Paul Ernest
This has also been quoted or misquoted as "There lives no man upon the earth who can give a final judgement upon what the most beautiful shape of man might be; God only knows that".
Albrecht Dürer: Citations en anglais
The Art of Measurement (1525).
Vier Bücher von menschlicher Proportion (1528).
The opening quotation of Introduction, Conjectures and refutations: The Growth of Scientific Knowledge by Karl Popper (1963).
As quoted in Dictionary of Scientific Biography (1970 - 1990) edited by M Steck.