The modern spirit arose from a union of the genius of the Italian people of the thirteenth century with antiquity, and the feeling for Nature had a share in the wider culture, both as to sentimentality and grasp of scenery.  Classic and modern joined hands in Petrarch.  Many Hellenic motives handed on by Roman poets reappear in his poetry, but always with that something in addition of which antiquity shewed but a trace—­the modern subjectivity and individuality.  It was the change from early bud to full blossom.  He was one of the first to deserve the name of modern—­modern, that is, in his whole feeling and mode of thought, in his sentimentality and his melancholy, and in the fact that ’more than most before and after him, he tried to know himself and to hand on to others what he knew.’ (Geiger.) It is an appropriate remark of Hettner’s, that the phrase, ’he has discovered his heart,’ might serve as a motto for Petrarch’s songs and sonnets.  He knew that he had that sentimental disorder which he called ‘acedia,’ and wished to be rid of it.  This word has a history of its own.  To the Greeks, to Apollonius, for instance,[4] it meant carelessness, indifference; and, joined with the genitive [Greek:  nooio]—­that is, of the mind—­it meant, according to the scholiasts, as much as [Greek:  lype] (Betruebnis)—­that is, distress or grief.  In the Middle Ages it became ’dislike of intellect so far as that is a divine gift’—­that disease of the cloister which a monkish chronicler defined as ’a sadness or loathing and an immoderate distress of mind, caused by mental confusion, through which happiness of mind was destroyed, and the mind thrown back upon itself as from an abyss of despair.’

To Dante it meant the state—­

                                       Sad
  In the sweet air, made gladsome by the sun,

distaste for the good and beautiful.

The modern meaning which it took with Petrarch is well defined by
Geiger as being neither ecclesiastic nor secular sin,[5] but

Entirely human and peculiar to the cleverest—­the battle between reality and seeming, the attempt to people the arid wastes of the commonplace with philosophic thought—­the unhappiness and despair that arise from comparing the unconcern of the majority with one’s own painful unrest, from the knowledge that the results of striving do not express the effort made—­that human life is but a ceaseless and unworthy rotation, in which the bad are always to the fore, and the good fall behind ... as pessimism, melancholy, world pain (Weltschmerz)—­that tormenting feeling which mocks all attempt at definition, and is too vitally connected with erring and striving human nature to be curable—­that longing at once for human fellowship and solitude, for active work and a life of contemplation.

Petrarch knew too the pleasure of sadness, what Goethe called ’Wonne der Wehmuth,’ the dolendi voluptas.