theory of historical trajectory
... that Karl Marx's theory of historical trajectory attempted to prove the long-term unsustainability of capitalism?
... that <a href="./Karl_Marx" id="mwBdU" rel="mw:WikiLink" title="Karl Marx">Karl Marx</a>'s <b id="mwBdY"><a href="./Theory_of_historical_trajectory" id="mwBdc" rel="mw:WikiLink" title="Theory of historical trajectory">theory of historical trajectory</a></b> attempted to prove the long-term unsustainability of <a href="./Capitalism" id="mwBdg" rel="mw:WikiLink" title="Capitalism">capitalism</a>?