(original review, 2009)
The Portuguese etymological dictionary of Jose Pedro Machado informs that the word aphorism derives from the Greek and arrived at the Portuguese language through late Latin aphorismu-, with the meaning of "limitation, brief definition, sentence". It adds that, in time (already documented in the 16th century), the term has come to be called "a brief and indisputable sentence, which sums up a doctrine."
Kafka resorted to the aphorism, what he called “Schreiben als Form des Gebetes” in his conversations (for example, with the poet Gustav Janouch, author of the book “Conversations with Kafka”, 1953) and in the course of his career as a writer. One of the main collections of these "short and indisputable sentences" was published in the small posthumous book “Er”, from the diary notes that the writer kept from 1909 to 1923-24.
If you're into stuff like this, you can read the full review.