John Hazelrigg

The provided text discusses the concept of pen names, also known as pseudonyms or nom de plumes, which are adopted by authors for their written works. It explains that authors might choose a pen name for several strategic or personal reasons. These can include making their name more distinctive, concealing their gender, separating different bodies of work, protecting themselves from potential repercussions for their writing, or consolidating the efforts of multiple authors under a single byline. The extent to which an author's true name is known can vary, ranging from being known only to the publisher to becoming widely recognized by the public.

The article lists various categories of authors, alphabetically from A to Z, where pen names are utilized. However, the specific extract provided for John Hazelrigg does not contain any biographical details, notable works, or specific contributions related to esoteric subjects. It primarily serves as a placeholder within a larger alphabetical listing of authors who employ pseudonyms. Therefore, based solely on this extract, no specific information about John Hazelrigg's individual literary contributions or the reasons behind any potential pen name usage can be determined.