I read philosophy, and a great deal of philosophical texts, including those by Nietzsche, Plato, Hume, and a great deal of others include a similar grammar that I do not understand: that an independent clause which is a question may begin with a lowercase letter if it is following another question.
Here is an example from Phaedo (by Plato):
"And is the soul in agreement with the affections of the body? [or] is she at variance with them?
Why is it permissible to lowercase 'or'?
Unfortunately I cannot recall any specific examples of this, but I remember having the exact same question when reading Nietzsche's Genealogy of Morals.
Is there any grammatical rule sanctioning lower case letters at the beginning of questions following other questions (perhaps if that question begins with a conjunction, or is directly related to the preceding question?)?
Not that it matters, but I quite like it. It looks unique and interesting to me.