Rubuta ci gaba don wannan sakin layi - Matthiessen yana ɗaya daga cikin maza da mata masu ilimi da yawa a duk faɗin waɗanda suka amsa da himma ga ɓarkewar juyin juya hali a Paris a 1789. A watan Yulin 1790, ya kasance daya daga cikin manyan masana ilimi na Hamburg kimanin tamanin waɗanda suka halarci "Bikin Juyin Juya Halin" wanda Sieveking ya shirya kuma aka gudanar a cikin lambun mashaya a Harvestehude don bikin ranar farko ta mamaye Bastille
Ka yi haƙuri. A lokacin hunturu na 1790/91 ya zauna a Paris, ya zama memba na "Club 87" kuma ya kulla dangantaka da de La Rochefoucauld. A watan Yulin 1791 ya dawo Hamburg inda aka zabe shi a matsayin memba na "Kollegium der Armenanstalt", wanda ke kula da Caspar Voght. Daga baya tafiye-tafiyensa zuwa Paris ya zama na yau da kullun, kuma ya mai da shi fifikon kansa don ba da tallafi ga mutanen Paris da ke cikin bukata. A lokacin shekarunsa na ƙarshe yana ba da tallafi ga iyalai tamanin, yana ziyartar su duka muddin ƙarfinsa ya ba da izini.