Sentence:  The preposterous altruism too!...Resist not evil. It is an insane immolation of self—as bad intrinsically as fakirs stabbing themselves or anchorites warping their spines in <WSD>caves</WSD> scarcely large enough for a fair-sized dog. 
Meaning of the word marked with <WSD> tags:  A large, naturally-occurring cavity formed underground or in the face of a cliff or a hillside.