Nothing escaped Lincoln's powers of philosophical and metaphysical analysis. He did not read the Bible and Shakespeare merely for pleasure, as people read novels. He could give excellent reasons for everything he did. Even in his most listless moods he never lost his firm grip on affairs, both general and individual. When he read a book it was because there was something in it which helped him to penetrate deeper into the recesses of life and character. He would study a passage or a chapter until he had assimilated its wisdom and its mystical import.

Lincoln was a natural critic. When Walt Whitman's "Leaves O' Grass" was first published a copy of the book was read and discussed by several of his friends in Springfield. Lincoln at once recognised the fact that a new poetic genius had appeared and he did not permit adverse opinions to influence his judgment. He cared nothing for the romantic in itself. He cared only for those phases of literature which induce serious philosophical or spiritual thought. While his partner read Carlyle, he read Shakespeare.

In the Spring of 1862 the President spent several days at Fortress Monroe awaiting military operations upon the Peninsula. As a portion of the Cabinet were with him, that was temporarily the seat of government, and he bore with him constantly the burden of public affairs. His favourite diversion was reading Shakespeare. One day—it chanced to be the day before the capture of Norfolk—as he sat reading alone, he called to his side Colonel Le Grand B. Cannon. "You have been writing long enough, Colonel," he said, "come in here; I want to read you a passage in Hamlet." He read the discussion on ambition between Hamlet and his courtiers, and the soliloquy in which conscience debates of a future state.