This paper documents an important development in Robert Boyle's natural-philosophical method – his use from the 1660s onwards of ‘heads’ and ‘inquiries’ as a means of organizing his data, setting himself an agenda when studying a subject and soliciting information from others. Boyle acknowledged that he derived this approach from Francis Bacon, but he had not previously used it in his work, and the reason why it came to the fore when it did is not apparent from his printed and manuscript corpus. It is necessary to look beyond Boyle to his milieu for the cause, in this case to the influence on him of the Royal Society. Whereas the Royal Society in its early years is often seen as putting into practice a programme pioneered by Boyle, this crucial methodological change on his part seems rather to have been stimulated by the society's early concern for systematic data-collecting. In this connection, it is here shown that a key text, Boyle's influential ‘General Heads for a Natural History of a Country, Great or small’, published in Philosophical Transactions in 1666, represents more of a shared initiative between him and the society than has hitherto been appreciated.