R Johnson was in Godwin's 1796 list between Pope 30.11.1793 and Tresham 14.12.1793, and in 1794 version (and Joseph Johnson was strangely absent from 1796 list). Richard Johnson (History of Parliament) 1753-1807 of 104 Pall Mall was a 'nabob' MP, son of Dr Johnson of the Hague, he married 1.3.1792 Sophia daughter of John Courtenay MP, and his sister Mary (1740-1827) married Alexander Blair (died 1816). His most frequent guests were the Courtenays and Mackintosh, the Blairs appear twice as does una Italiana, and most of Godwin's visits are for tea. Johnson first came to Godwin's, along with Stewart, on a Sunday morning when Smith (still unidentified) was breakfasting with Godwin, as he did most Sundays; he came the next Sunday morning 8.12.1793, then Godwin called on him 13.12.1793 but he was out, Godwin took tea at his on 20.12.1793 and they talked of Voltaire & Cicero, he called on Sunday (wrongly called Monday on the GD website) 29.12.1793 but too late and Godwin was out, then Godwin took tea at his on 2.1.1794, when he was clearly identifiable by one guest being his brother-in-law K Courtney, then Godwin dined there on 16.1.1794, and this time Johnson's father-in-law Courtenay and brother-in-law Blair were there, as well as James Mackintosh, and Kenneth Courtenay turned up with Stewart (presumed by GD website to be 'Walking' Stewart but possibly one of the Stuart brothers whose sister Mackintosh had married), then on 1.2.1794 Godwin took tea there with Courtenays & Blairs, 3.2.1794 Johnson dined at Mackintosh's, 19.2.1794 tea at Johnson's with una Italiana (who was there again as 'una Ita' with the Coutenays on 2.11.1795), 5.3.1794 tea there with Morse and Jon. Scott, and on 23.3.1794 Johnson called again at Godwin's on a Sunday.
Before all this there had only been three Johnson entries in Godwin's diary; the famous dinner at Joseph Johnson's on 3.11.1791 when Godwin met Tom Paine & Mary Wollstonecraft; and two calls on Johnson, on 11.4.1793 and 18.4.1793, the first one directly after calling on George Robinson, Godwin's publisher. They were very likely on Joseph Johnson, but there's no further entry that seems clearly to refer to Joseph Johnson until 21.11.1795, when Godwin called on him, again straight after seeing Robinson; then he called on him on 12.12.1795, and noted St Paul's, where Joseph Johnson lived and worked. Another call on 5.3.1796 was probably Joseph though it could just have been Richard, and then on 9.8.1796 Godwin dined again at Joseph Johnson's for the first time in nearly five years, and he used 'J Johnson' just that once. Thereafter Joseph was just Johnson, and Richard had already become R Johnson. The dinners at Joseph's were on Tuesdays till 1801 when they shifted to Wednesdays, going back to Tuesdays late in 1806. Godwin attended more than a hundred of them before, on 28.7.1807, there was one where neither Fuseli, Bonnycastle nor Newnum was present. This pattern is so regular that it provides further evidence that none of the meals at Johnson's Godwin attended in 1794 and 1795 were at Joseph's, for none of them ever featured any of his regular guests. Calls and meetings in 1794 and 1795 are more ambiguous, and complicated by the presence of two other Johnsons, who like all Richard Johnsons without an initial R, have been assigned to Joseph in the GD website.
9.10.1794, 10.10.1794 and 25.6.1795 all in Warwickshire can be clearly assigned (see Johnson, Robert Augustus). Johnson, adv at King's 23.1.1795, 'Johnson clerk of arr' there on 30.1.1795, and Johnson adv at King's 19.2.1795 seem to belong to another Johnson. I haven't identified him from the Law Lists which do name some Clerks of Arraigns, but it was said that John King had his own tame clerk of arraigns to warn him of impending lawsuits. I suspect he was also the 4.2.1795 tea at Johnson's Kentish Town as this came 5 days after dining with Godwin at King's and Richard Johnson was too rich to live in Kentish Town. And 28.1.1796 'talk about' along with Raffael & Garrick was surely the late Dr Samuel Johnson DNB 1709-1784.
To return to Richard Johnson, Godwin called at his on 27.3.1794, took tea there 25.4.1794 & 16.5.1794, called to find him out 29.5.1794, met him 19.6.1794, took tea there 29.7.1794 & 11.9.1794 (both times with Courtenays), on 4.1.1795 Johnson called once again on a Sunday morning after Smith breakfasted, Godwin dined at his 8.2.1795 with Middleton (probably Nathaniel Middleton, Johnson's banking partner and brotherin law of John & Robert Morse - see 5.3.1794 above), met him 6.3.1795, and took tea at his 2.4.1795. These last three entries might not be Richard, though in that case they could be the clerk of arraigns as easily as Joseph Johnson; what most puts them in doubt is that on 18.4.1795 Godwin first used the initial R Johnson when he called. Maybe he was slowly beginning to recognise there were too many Johnsons in his life, but he still reverted to using just Johnson for Richard Johnson. On 27.4.1795 Godwin dined at Johnson's with T Taylor; he had called on T Taylor and found him not in only two days before, so presumably had left him the invite to Johnson's. On 21.6.1795 Godwin took tea at Johnson's with the Johnstones, and on 24.7.1795 & 27.8.1795 he called on R Johnson (not in); then on 2.11.1795 he had tea at Johnson's (no initial) but with the Courtenays and 'una Ita' (see 19.2.1794 above); and on 28.12.1795 tea at R Johnson's. The calls on Joseph Johnson of 21.11.1795 and 12.12.1795 had now occurred, as plain Johnson; so 15.2.1796 meet Johnson is particularly ambiguous, but something tells me Richard was much more likely to be out and about in town than Joseph was. But from there on Godwin seems to consistently use 'R Johnson' when he took tea there 24.2.1796, dined there 29.2.1796, met him 2.4.1796, dined there 15.12.1796, took tea there 10.3.1797, and never took a meal there again but met him on 10.5.1797, 15.7.1798, 19.1.1799, 21.2.1799, 21.4.1799, 30.10.1799, 19.2.1800, 24.3.1800, 26.6.1800, & 16.1.1802.
There is no reason to think Joseph Johnson ever made a call on Godwin except during the few months of Godwin's marriage to Mary Wollstonecraft and just after her death. Godwin called on Johnson on 2.2.1797 and this is likely to be Joseph as four days later on 6.2.1797 Godwin, Johnson & Wollstonecraft visited Bedlam together. Godwin continued to attend Joseph's dinners, but on 8.4.1797, shortly after Godwin's wedding, he called on Johnson, there was an altercation, and the next day 9.4.1797 Johnson dined with the newly married couple. On 9.7.1797 'adv Johnson' at Godwin's, and three days later on 12.7.1797 the Godwins took tea at Johnson's with no other guests mentioned. Fuseli's presence was the presumable reason why Mary Wollstonecraft hadn't been attending Johnson's dinners. Then in the days before her death Johnson called twice, on 1.9.1797 and 4.9.1797, and after it he called on 12.9.1797 and 'adv Johnson' at Godwin's on 22.9.1797 & 23.9.1797. There are two Johnson entries early in 1798 which might apply to Richard Johnson rather than Joseph. On 6.1.98 Johnson breakfasted at Godwin's, and on 12.2.1798 Godwin dined at Fordyce's with Clarke, Carlisle, Johnson & Stewart. The connection with Stewart who had perhaps introduced Richard Johnson to Godwin made me wonder about this. Changed my mind about the second one, see Clarke, Dr John; which also makes the first seem more likely Joseph Johnson, concerned perhaps about Mary Wollstonecraft's legacy and the impending publication of Godwin's Memoirs of her.
R Johnson turned up again at Tuffin's on 29.4.1806, and on 7.5.1806 Godwin called on R Johnson. On 4.6.1806 Godwin called on 'J Johnson', a one-off usage probably evoked by the call on R Johnson a month before. On 24.9.1806 Godwin sought R Johnson but he never featured in the diary again and he died in 1807.
20.7.1806 Johnson's Purser's Crs & 26.10.1806 Johnson's PC which have been left uncoded in GD website were clearly Joseph Johnson at his country box at Pursers Cross in Fulham