Rousseau - Discourse on the Origin of Inequality (1755) 

As ideas and feelings succeeded one another, and hearts and minds were cultivated, the human race became more sociable, contacts increased, and bonds grew tighter. People developed the habit of gathering together in front of their huts or around a large tree; song and dance, true children of love and leisure, became the entertainment, or rather the occupation, of the idle men and women thus flocked together. Each person began to gaze on the others and to want to be gazed upon himself, and what came to be prized was public esteem. Anyone who best sang or danced; he who was the most handsome, the strongest, the most skilful, or the most eloquent came to be the most highly regarded, and this was the first step toward inequality and toward vice. These first preferences gave rise, on the one side, to vanity and scorn, and on the other, to shame and envy; and the ferment produced by these new leavens eventually led to concoctions ruinous to happiness and innocence.