As you know, I have been pondering the impact of Sigmund Freud. Would our culture be substantially different if he had never lived?
The Freud legend is that he single-handedly changed the way that we view ourselves. It is argued that no matter how many of his ideas we have come to reject, enough of his framework has become embedded in our thinking that we are, like it or not, all Freudians now.
For me, one way to approach this issue is to consider a possible analogy with the Beatles. Were they important in shaping the culture of the 1960s, or were they primarily shaped by what was happening around them? The same questions can be asked about Freud.
Note that the impact of the Beatles was different post-1965 from what it was in 1963-1964. This is true both in terms of music and in terms of lifestyle. Had the Beatles remained stagnant after 1964, it is likely that they would have had less enduring significance.
The Beatles dominated pop music in 1964. But although their sound was distinctive, their music up to that point was pretty basic. Their main fan base consisted of adolescents.