"If Lacan presumes that female homosexuality issues from a disappointed heterosexuality, as observation is said to show, could it not be equally clear to the observer that heterosexuality issues from a disappointed homosexuality?"
Butler includes many such reversals of expectation like this quote in her book. The key here is riddle. She uses contrary logic or circular reasoning to point out the absurd nature of common arguments against homosexuality and the equality of women. She uses these strategies to draw attention to construction.
"To operate within the matrix of power is not the same as to replicate uncritically relations of domination."
Butler believes that women should participate in the hierarchy of competition. She argues, however, that women are often excluded from this participation because the system is designed by men and thus male-skewed. In addition, many women are considered traitors for adapting to the system according to the predominantly male handbook. This quotation explains how participation does not equal lack of disagreement. A woman may challenge the system while still agreeing to participate in power dynamics.
"If the immutable character of sex is contested, perhaps this construct called 'sex' is as culturally constructed as gender; indeed, perhaps it was always already gender, with the consequence that the distinction between sex and gender turns out to be no distinction at all."
Butler provides extensive argument as to the construction of the idea of "sex." She believes that "sex" is a human concept which does not necessarily refer to anything natural, or at least not anything complete. In this quote, she argues that both sex and gender are related so closely that they, in relationship, define the concept which society has termed "sex."
"Learning the rules that govern intelligible speech is an inculcation into normalized language, where the price of not conforming is the loss of intelligibility itself."
Language is used by society to set boundaries upon acceptable behavior. In order to relate to your fellow man, you must first follow certain rules. Then you will be understood.