Feminist separatism is the theory that feminist opposition to patriarchy can be achieved through women's separation from men. Much of the theorizing is based in lesbian feminism. Author Marilyn Frye describes feminist separatism as "separation of various sorts or modes from men and from institutions, relationships, roles and activities that are male-defined, male-dominated, and operating for the benefit of males and the maintenance of male privilege – this separation being initiated or maintained, at will, by women." Cultural critic Alice Echols describes the emergence of a lesbian separatist movement as a response to homophobic sentiments expressed by feminist organizations like the National Organization for Women. Echols argues that "...the introduction of (homo)sex troubled many heterosexual feminists who had found in the women's movement a welcome respite from sexuality". Echols considered separatism as a lesbian strategy to untie lesbianism from sex so heterosexual women in the feminist movement felt more comfortable. Cell 16, which was founded in 1968 by Roxanne Dunbar, has been cited as the first organization to advance the concept of separatist feminism. Cultural historian Alice Echols credits Cell 16's work for "helping establishing the theoretical foundation for lesbian separatism." Echols cites Cell 16 as an example of heterosexual feminist separatism, as the group never advocated lesbianism as a political strategy. In No More Fun and Games, the organization's radical feminist periodical, members Roxanne Dunbar and Lisa Leghorn advised women to "separate from men who are not consciously working for female liberation." Instead, they advised periods of celibacy, rather than lesbian relationships, which they considered to be "nothing more than a personal solution". Proponents of feminist separatism have varied opinions on the meaning of feminist and lesbian separatism; major debates include the degree to which women should separate from men, whether it is a strict ideology or a strategy, and how it works to benefit women.