Today let us consider the idea of birthdays...
It is because continuity is a foremost aim, our human nature responds very keenly to the birth of a child. Every birthday is a testimonial to man's longing for continuity.
[SLJ "Commencement" in Catholic Essays 171]
Continuity was the gist of Duhem's view of history, but because he viewed that continuity as something living he had eyes for the struggle and delayed outbursts of new growth, characteristic of all life. Above all he had an eye for the all-important question about living continuity, namely, its vital beginning. The preface of the second Leonardo volume contained two phrases which by their conspicuous place must have struck the eyes of all readers. In the first Duhem spoke of 'Christian thought, which at the end of the thirteenth century broke the tyranny of peripatetic philosophy.' In the second he referred to the contact made during the sixteenth century by Italian thinkers with ancient Greek geometry, which made them more receptive to the teaching of the Parisian masters of the 14th century: 'The contact infused into them a new life of which the renaissance of science is a witness.' Few readers went as far as Note F in the end of the book, where Duhem discussed the medieval break with the Aristotelian opposition to the plurality of worlds, or more specifically, to the infinity of 'worlds'. The break, which ultimately made possible the formulation of the concept of linear inertia, was of utmost importance for the future of science. Even more important had therefore to appear the force, Christian awareness of the Creator's unlimited powers, which made that break possible. This is why Duhem accorded decisive symbolic significance to the condemnation on March 8, 1277, by Etienne Tempier, Bishop of Paris, of 216 propositions, among them the one denying the possibility of the plurality of worlds. Duhem felt that 'if we were to specify the birthdate of modern science, we would undoubtedly choose that year, 1277. Such was the debut of a phrase, which he was to repeat emphatically in evidence of the importance he attributed not so much to a mere date but to the question of live birth, the fundamental precondition of all continuity, including the continuity of growth, be it biological or intellectual.
These three phrases anticipated the gist of the third volume of the Leonardo studies, possibly the most dramatic volume ever published on the history of science.
[SLJ Uneasy Genius: The Life and Work of Pierre Duhem 393-4]
A personal footnote from me: it was on this day five years ago that I was a guest of Father Jaki for lunch. We talked about a number of things, including numbers...
SLJ: How old are you?
Dr. T: I'll answer in the form of a riddle.
SLJ: Go ahead!
Dr. T: On my last birthday I was 48. On my next birthday I will be 50.
SLJ: (thinking) How is this possible? (thinks some more) Ah. Happy birthday!
Please pray for me, Father, and for all of the members of the Duhem Society.