Human, All-Too-Human: A Book for Free Spirits, Part 1 Complete Works, Volume Six

Thoughts on Man, His Nature, Productions and Discoveries Interspersed with Some Particulars Respecting the Author

On the Relations of Man to the Lower Animals

The Works of Aristotle the Famous Philosopher Containing his Complete Masterpiece and Family Physician; his Experienced Midwife, his Book of Problems and his Remarks on Physiognomy

Manhood of Humanity.

Human Life

We Moderns: Enigmas and Guesses

The Kingdom of Man

The Universal Kinship

El Hombre Mediocre: Ensayo de psicologia y moral

The Making of a Man