What did Thomas Carlyle mean by calling overly respectful biographies “vacuum-biographies”?

Thomas Carlyle used the term “vacuum-biographies” to criticize the 19th-century trend of producing overly respectful, sanitized accounts of people's lives.1

He believed that many biographies of his era were stifled by an excessive insistence on respectability and decorum, which came at the direct expense of candor and truth. By prioritizing a "mealy-mouthed" approach that avoided the complexities, eccentricities, or darker realities of a subject's life, these authors created works that lacked substance or genuine human depth—essentially "vacuums" where the actual person should have been.1

Carlyle’s critique highlights a fundamental ethical principle in biographical writing: the necessity of honesty. By favoring hagiography—or the practice of portraying a subject as flawless and saintly—these biographers failed in their duty to provide a truthful account of the "earthly pilgrimage" of the individual. For Carlyle, such evasions were a disservice to the subject and the reader alike, as they obscured the reality of the human experience in favor of a hollow, idealized image.12