serious thought

References in classic literature ?
She was not pleased to see Julia excluded from the play, and sitting by disregarded; but as it was not a matter which really involved her happiness, as Henry must be the best judge of his own, and as he did assure her, with a most persuasive smile, that neither he nor Julia had ever had a serious thought of each other, she could only renew her former caution as to the elder sister, entreat him not to risk his tranquillity by too much admiration there, and then gladly take her share in anything that brought cheerfulness to the young people in general, and that did so particularly promote the pleasure of the two so dear to her.
So they sat down to consider what they should do, and after serious thought the Scarecrow said:
Anne of Austria reflected for a moment, seemingly absorbed in sad and serious thought.
She was assured of his affection; and that heart in return was solicited, which, perhaps, they pretty equally knew was already entirely his own; for, though Henry was now sincerely attached to her, though he felt and delighted in all the excellencies of her character and truly loved her society, I must confess that his affection originated in nothing better than gratitude, or, in other words, that a persuasion of her partiality for him had been the only cause of giving her a serious thought.
In the first moment of serious thought that I gave to the matter I recognized the city of my dream as Edinburgh, where I had never been; so if the dream was a memory it was a memory of pictures and description.
She jested with Mary's father about the coming union between the two families, without one serious thought of the future--without even a foreboding of what might happen when my father returned.
The sixteen sonnets which belong here show how nobly this form could be adapted to the varied expression of the most serious thought, but otherwise Milton abandoned poetry, at least the publication of it, for prose, and for prose which was mostly ephemeral.
The only serious thought it cost her was a thought in which Kirke was concerned.
And then she mentioned how often she had heard of Lady Southdown from that excellent man the Reverend Lawrence Grills, Minister of the chapel in May Fair, which she frequented; and how her views were very much changed by circumstances and misfortunes; and how she hoped that a past life spent in worldliness and error might not incapacitate her from more serious thought for the future.
Rochester might probably win that noble lady's love, if he chose to strive for it; is it likely he would waste a serious thought on this indigent and insignificant plebeian?
Well, perhaps, that's what young Mr d'Urberville means," he admitted; "and sure enough he mid have serious thoughts about improving his blood by linking on to the old line.
I had serious thoughts of getting a pitcher of water and extinguishing that light too; but it was evident his curiosity was too keenly excited to be quenched by that, and the more I manifested my anxiety to baffle his scrutiny, the greater would be his determination to persist in it besides it was too late.