Descartes’ philosophy of “I think, therefore I am,” while referencing Kant, Hegel, Husserl, Heidegger, Aristotle, and Plato when defining the history of European thought. Although the pope writes to a worldwide audience, he also speaks specifically of the Catholic faith, including references not only to the Sacred Scriptures, but also many saints: Augustine's City of God, John of the Cross and his Ascent of Mount Carmel, Thomas Aquinas and the Summa Theologica, and many more. Praise Reception of this work of John Paul II range from “With the humility and generosity of spirit for which he is well known, John Paul speaks forthrightly to all people” to “the Pope emerges as the master of the flat statement, the bland certainty. Metaphor, anecdotes, humour, imagination rarely trouble his style; he prefers the long pedantic plod through Aristotle and Plato, St Paul, Augustine, St Thomas Aquinas, Descartes, Pascal, Kant, Hegel, Husserl and Heidegger” Criticism The Pope's negative portrayal of Buddhism received widespread criticism within the various branches of Buddhism across the world. In response to receiving several letters from Poland, from individuals and from a publishing house, asking him to comment on it, Thinley Norbu Rinpoche (one of the key teachers in the Nyingma lineage of Tibetan Buddhism) wrote the book Welcoming Flowers from across the Cleansed Threshold of Hope: An Answer to the Pope's Criticism of Buddhism to address the "serious, gratuitous misrepresentations of Buddhist doctrine which seemed to be based on misunderstandings" contained within Crossing the Threshold of Hope. The release of the book in Sri Lanka on the eve of the Pope's January visit to this country stirred up waves of indignation in the Buddhist community that spread as far as the Vatican. The Buddhist prelates announced that they would not attend an inter-religious meeting requested by the Pope unless he formally retracted his unfavorable remarks about Buddhism. Although on arrival the Pope tried to appease the feelings of Buddhist leaders by declaring his esteem for their religion, even quoting the Dhammapada, he fell short of proffering a full apology, and this did not satisfy the Sangha elders. The New York Times cited criticism from Sri Lanka Buddhists, saying: In his book, the Pope uses language that Buddhists here say they found offensive, notably its reference to nirvana as a state of "indifference with regard to the world" and its assertion that the Buddhist doctrine of salvation through nirvana