However, Sraffa broke off his weekly conversations with Wittgenstein in 1946 despite the latter's protests; and when the philosopher said he would talk about anything Sraffa wanted, "'Yes', Sraffa replied, 'but in "your" way'". Sraffa and Wittgenstein influenced each other deeply. While Wittgenstein made his famous turn from the "Tractatus Logico-Philosophicus" to the "Philosophical Investigations" wherein he jettisoned the previous idea that the world comprised an atomistic set of propositional facts for the notion that meaning derives from its use within a holistic self-enclosed system. Analogously, Sraffa was rebutting the neoclassical paradigm which was similarly atomistic and individualistic (see criticisms of neoclassical economics). While there are disputes about how to interpret Sraffa none dispute Sraffa's influence. After the publication of" Production of Commodities by Means of Commodities", Sraffa's thought became the subject of a great debate. Sraffa was described as a shy and very reserved man who was devoted to study and books. His library contained more than 8,000 volumes, many of which are now in the Trinity College Library. A popular anecdote claims that Sraffa made successful long-term investments in Japanese government bonds that he bought the day after the nuclear bombing on Hiroshima and Nagasaki. Another version of this is that Sraffa bought the bonds during the war when they were trading at distressed prices as he was convinced that Japan would honour its obligations (Nicholas Kaldor, pp. 66–67). In 1961, before the Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel had been created, he was awarded the Söderströmska Gold Medal by the Royal Swedish Academy of Science. In 1972, he was awarded an honorary doctorate by Sorbonne and in 1976 received another one from Madrid's Complutense university.