Catherine MackKinnon and Andrea Dworkin were among those feminists who lead the charge against pornography, so to speak, calling it what amounts to a central pillar in the edifice of patriarchal oppression.
However, humans have only had free and easy access to visual pornography for the past few decades, maybe the past century, at most; and even literary pornography, like Fanny Hill, only dates back to the 18th Century. Before this, the inability to mass-produce pornographic materials seems to imply that it can't have had much the same impact as it could potentially have today - and many such depictions were on urns, floor mosaics or other objects with further purposes, so they weren't there strictly for sexual arousal.
Yet it doesn't seem unreasonable to say that Western civilization has seen women forced into the status of second-class citizens for many more centuries than that, even millenia. So how can pornography be the central factor, or even a central factor, in the oppression of women? Or is it that it is the only important factor that remains (after, say, religion and antiquated views of women as naturally, biologically inferior)?