De Quincey manages to put into practice avant la lettre the essential precepts of Macel Schwob, for the art of biography as an artistic genre, and that are synthesized in the presentation of significant details, magnified by technical procedures of writing. His illustrations of the grain of sand in Cromwell's urethra or Cleopatra's nose are unforgettable.

As for Kant, the founder of Transcendental Analytics, he appears to us inscribed in the inconsequential circumstance of his daily life and his inflexible habits.

The goal of this genius is revealed to us in the brand of beer he drank and in the elaborate device he devised to keep stockings, no less than his philosophical writings. De Quincey makes one feel throughout the book: that the thinker who had raised criticism above Theology and Metaphysics would not ignore the news in the newspapers, nor the mortality of cats, and would arrive even to criticize and reform certain natural acts such as walking or breathing.