 As we have seen, Herder also, in tension but not contradiction with this principle of sociality, holds that (even within a single period and culture) human minds are as a rule deeply individual, deeply different from each other—so that in addition to a generalizing psychology there is also a need for a psychology oriented to individuality. This is an important idea that has strongly influenced many subsequent continental thinkers (for example, Schleiermacher, Nietzsche, Proust, Sartre, and Manfred Frank). Herder himself advances it only as an empirically based rule of thumb. By contrast, a prominent strand in Schleiermacher and Frank purports to establish it as an a priori universal truth. However, here again Herder’s original version is arguably the more plausible one.