There is no wish more natural than the wish to know.
Ceremony forbids us to express by words things that are lawful and natural, and we obey it; reason forbids us to do things unlawful and ill, and nobody obeys it.
The land of marriage has this peculiarity: that strangers are desirous of inhabiting it, while its natural inhabitants would willingly be banished from thence.
There is no desire more natural than the desire of knowledge. (Il n'est desir plus naturel que le desir de connaissance)
Natural inclinations are assisted and reinforced by education, but they are hardly ever altered or overcome.