Structure J. T. Young writes: At its nexus, it was an association of personal friends. Hartlib and Dury were the two key figures:
Comenius, despite their best efforts, always remained a cause they were supporting rather than a fellow co-ordinator. Around them were
Hübner,
Haak,
Pell,
Moriaen,
Rulise,
Hotton and
Appelius, later to be joined by
Sadler,
Culpeper,
Worsley,
Boyle and
Clodius. But as soon as one looks any further than this from the centre, the lines of communication begin to branch and cross, threading their way into the entire intellectual community of Europe and America. It is a circle with a definable centre but an almost infinitely extendable periphery. Examples given of the "periphery" are
John Winthrop and
Balthazar Gerbier.
Themes • Agriculture and horticulture:
Ralph Austen,
John Beale,
Robert Child,
Cheney Culpeper,
Cressy Dymock,
Gabriel Plattes,
Adolphus Speed. • Alchemy, chemistry, mineralogy:
Robert Boyle,
Frederick Clod, Cheney Culpeper,
John Worthington,
Ezechiel Foxcroft,
John French,
Johann Moriaen, Gabriel Plattes. • Finance: Cheney Culpeper, William Potter • Mathematics: John Pell,
Robert Wood. • Medicine:
William Rand,
Thomas Coxe • Pansophism: Hartlib and Dury were close allies of
Comenius. • Protestantism:
Sarah Hewley, John Dury,
John Sadler,
John Stoughton. • Settlement of Ireland:
Gerard Boate and his brother
Arnold Boate,
William Petty,
Benjamin Worsley.
Education Educational reform was topical and central to the pansophist programme. Hartlib compiled a list of "advisers", and updated it. It included
Jeremy Collier, Dury,
Thomas Horne,
Marchamont Nedham,
John Pell, William Rand,
Christian Ravius,
Israel Tonge, and
Moses Wall. The staff proposed for
Durham College was influenced by the Circle's lobbying.
John Hall was another associate who wrote on education. In the period 1648–50 many works on education appeared from Circle authors (Dury, Dymock, Hall,
Cyprian Kinner, Petty,
George Snell, and Worsley). A letter from Hartlib to
John Milton prompted the tract
Of Education (1644), subtitled
To Master Samuel Hartlib. But Milton's ideas were quite some way from those of the Comenians. Individuals involved with the Hartlib Circle played an important role in Sweden's scientific revolution, as they travelled to consult on educational and religious reform, as well as tutored Swedish students who were sent abroad.
The problem of the "Invisible College" Robert Boyle referred a few times in his correspondence to the '
Invisible College'. Scholarly attention has been paid to identifying this shadowy group. The social picture is not simplistic, since
en masse Hartlib's contacts had fingers in every pie. Margery Purver concluded that the Invisible College coincided with the Hartlib-led lobbyists, those who were promoting to the Parliament the concept of an Office of Address. The effective lifetime of this idea has been pinned down to the period 1647 to 1653, and as the second wave of speculation on the ideal society, after Comenius left England. In the later Interregnum the "Invisible College" might refer to a group meeting in
Gresham College. According to
Christopher Hill, however, the
1645 group (the Gresham College club that was convened from 1645 by
Theodore Haak, certainly a Hartlibian) was distinct from the Comenian Invisible College.
Lady Katherine Ranelagh, who was Boyle's sister, had a London
salon during the 1650s, much frequented by
virtuosi associated with Hartlib. ==Projects==