One of the most distinguished European travellers drawn to Persia in Safavid times, Sir John Chardin, records a native saying in these terms: “Le doute est le commencement de la science; qui ne doute de rien n'examine rien, qui n'examine rien ne découvre rien, qui ne découvre rien est aveugle et demeure aveugle”. And he goes on to place both Persian and Chinese science next to that of Europe in achievement, qualifying his statement by adding that certain theorems which are regarded as new in the West are, in fact, to be found in the Persian and Arab books. But Chardin was impressed by the legacy of the past, for Islamic science, which had a strong Persian element, reached its zenith with Ibn Sīnā, al-Bīrūnī, 'Umar Khayyām, al-Khāzinī, and al-Tūsī, and, apart from a late burst of activity in Timurid times attributable to Ulugh Beg and his school, was then in decline. Medicine alone continued to make new advances.

There are, nevertheless, several influences which go to make this period in the history of science one of peculiar interest. Persia was a place of exchanges in ideas rather than a focus of original discovery. The protracted and bitter struggle between the Safavid monarchs and the Ottoman Turks, in the course of which the Persians became familiar with embassies from European courts, and Anthony Sherley is said to have suggested to Shah 'Abbās I an alliance with the Christian powers, not only generated an interest in technology, for the shah's armies were initially deficient in the heavier weapons of war; it also enabled Persia to know something of the scientific revolution which was gaining in momentum and influence in western Europe.