Sentence:  If he wishes to enjoy an hour in his private study, it is not pleasant to be obliged all the time to listen to noises in the next room, even if made by his own servants or his own children. For members of a family themselves require at times to <WSD>seclude</WSD> themselves from other members of the family; — there are business matters to be talked of; there are projects which children or servants should not hear; there are numberless things which the heads of a household wish to discuss by themselves. 
Meaning of the word marked with <WSD> tags:  To shut off or keep apart, as from company, society, etc.; withdraw (oneself) from society or into solitude.