R. Aharon Lichtenstein, Varieties of Jewish Experience, pp. 251-252:
[W]e need to consider what has popularly become known as “the slippery slope”–the concern that acceptance of certain innovations, even if they are halakhically tenable, may invite pressures for further progressive change, resulting, incrementally, in the erosion of traditional sensibility or even outright halakhic violation. This issue has been raised most vigorously with respect to various initiatives concerning the role of women. Within the Torah world and the rabbinic establishment, response to these has been widely divergent. Some have contended that what the Shulhan Arukh does not proscribe could be regarded with favor. Others have rejected this premise as a general approach; and they have further resisted any innovation, particularly if fuelled by feminist ideology, on the grounds that it might lead to further demands or trigger a domino effect. And, there is, of course, a spectrum of intermediate responses. Here again, we need to maintain a dual watch. The concern about the slippery slope is, in principle, both legitimate and genuine. It is firmly rooted in Hazal, who anchored many gezerot upon it, as graphically illustrated in the Rambam’s explanation as to the basis of the prohibition against fowl cooked with milk [Mishneh Torah, Hilkhot Mamrim 2:9]…
In this case, one encounters outright de-oraita violation early in the chain. The principle is in force, however, even when that is not the case. Yet, in applying the principle, two factors need to be weighed. We shall have to evaluate, first, the likely course of events. How truly slippery is the slope? What innovation is likely, and how likely, to generate which kind of pressures? Second, we shall need to examine at what cost–whether in the form of possible alienation of certain constituencies or in the impairment or dilution of the quality of spiritual life–the presumed security of an ultra-conservative stance is being attained. This last factor will itself require dual consideration, as we strive both to perceive the prospects of various alternative scenarios on the ground and to determine how much weight to assign this particular concern.
As for myself, I presume that, with respect to both the women’s issues, specifically, and the fear of the slippery slope, generally, I find myself somewhere in the middle–enthusiastically supportive of some changes, resistant to others, and ambivalent about many; but I take it that this is not the venue for dealing with the details of various agendas.