I presume that both of these are quotations from literary sources. I am not familiar with the first, but the second is of course from Shakespeare's Hamlet. If the first quotation is also from an old source, I can tell you that both sentences simply reflect the punctuation used in those times.
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Anonymous1. Of course we are all fictions, [that] make us feel tenderness for each other rather than contempt.2. To be or not to be, [that] is the question.In (2), "that" is a demonstrative pronoun, not a relative pronoun. It would not make sense to change it to "which".