His first teaching post was as a lecturer in Psychology and Education at the Cambridge Women's Training College, which he held for several years.

[6][7] In 1902 he was elected a Fellow of King's College, and appointed to the (newly-created) Sidgwick Lecturership, positions he held until his death.

[11] In 1912 (at Bertrand Russell's request) Johnson did attempt to 'coach' Ludwig Wittgenstein in logic but this was an arrangement that was both brief and unsuccessful.

That, though "very able", he was "lacking in vigour" and had "published almost nothing" is a matter Bertrand Russell commented upon unsympathetically in a letter to Ottoline Morrell of 23 February 1913.

[14] Johnson's obituary in The Times, penned by J. M. Keynes, more kindly reports that "his critical intellect did not readily lend itself to authorship.

The preface to the first volume carries the acknowledgement: "I have to express my great obligations to my former pupil, Miss Naomi Bentwich, without whose encouragement and valuable assistance in the composition and arrangement of the work, it would not have been produced in its present form.

[23][6] Logic ensured his election to the British Academy and won him honorary degrees from the universities of Manchester and Aberdeen.

[24] Though conceding that Logic was "dated", even at publication, Sébastien Gandon argues that it would be unfair, given "the richness of his thought", to see Johnson "only as a member of the British logic 'old guard' pushed aside by the Principia Mathematica" of Alfred North Whitehead and Bertrand Russell.

The first two, both published in the Cambridge Economic Club, being 1891's "Exchange and Distribution" and 1894's "On Certain Questions Connected with Demand" (the latter being co-written with C. P.

[33][2] Prior to the latter he would also write fourteen entries for the first edition of R. H. Inglis Palgrave's Dictionary of Political Economy (1894-1899).