Life and Suffering

The perhaps cardinal tenet of Schopenhauer's doctrine is that "all life is suffering" (from #56 of World as Will and Representation).  He derives it from: 1. Life is Will-to-Live; 2. Will-to-Live is constant striving; 3. Striving can be, at best, only temporarily satisfied; and 4. Dissatisfaction is Suffering.  Now, as has been previously discussed, #1 is problematic, because he bases it on a contingent volitional interpretation of his own inner experience.  Furthermore, #3 entails that at least some striving is satisfied, and, hence, that not "all" Will-to-Live is suffering.  So, he shows no more than that his own experience is predominantly unsatisfactory, which might resonate on occasion with others, but which is inadequate as the cardinal tenet of a universal doctrine.