use of may as a variant seems to be less common. So far as the evidence goes, there is no apparent difference in meaning between the periphrasis with should and that with might (or may), both implying, as Murray (s.v. a/raid, 2, c) puts it "a deprecated contingency of which there is danger". See also Murray, s.v. shall, 22, e. Alphabetical arrangement of the quotations as indicated in 20, a)
i. * Darneley Place is so near London that I am always af raid
lest some fine and valuable picture should be missing. Rich. Baoot, Darneley P1 a c e, Ch. IV, 42. When ladies leave the Gallery for tea there is no need for them to fear lest they should lose their seats. Grap h, 1889, 279.
a girl with large possessions is always suspicious lest a man should pretend to love her for the sake of hermoney. Besant, All Sorts and Cond. of Men, Ch. V, 45. ** I dreaded lest any stranger should nottce me and speak to me. G. Eliot, Dan. Der., I, III. Ch. XX, 332. I feared lest I should be deceived. Bain, H E. Gr., 113. My only tenor was lest my father should follow me. G. Eliot, Dan. Der, I, III, Ch. XX, 329. Pen trembled lest the other should discover hls emotion. Thack., P e n d, I. Ch. V, 60.
ii. * There is considerable anxiety lest the evacuation may be
in some way evaded or modified. Westm. Gaz, No. 8179, 2a.
I fear lest they may be won already. Lytton, M y N o v e I, II, VIII, Ch. IV, 32. ** Robert saw that she was afraid lest she might have said something discourteous.Mrs.Ward, Rob. E1 sm, I,.68.T. She was taken with such anxious, earnest alarm lest the temptation might some day prove too strong for me that [etc] Mrs. Gask, C r a n f, Ch. XIV, 258. A horrible doubt came into my mind lest the dog might be loose. Con. Doyle, S h e r 1. H o 1 m, II, 269. T. She was urged by the fear lest her anticipated misfortunes might be held retributive. G. Eliot, M111, I. Ch. IX, 84. His terror was excited lest he might aclually have setn his ancestor's ghost. Miss Yonqe, The Heir of Rede, f, Ch. V, 76. T.
Also would, as a tense-auxiliary, is occasionally met with in subordinate statements introduced by lest. Of the analogous use of shall or will no instances have come to hand. I was afraid test she would be displeased. Mrs. Gask, Cranf, Ch. D, 44.