Quote by Thomas Malthus
"Thankfulness for blessings increases happiness."
More from Thomas Malthus
"The power of population is so superior to the power of the earth to produce subsistence for man, that premature death must in some shape or other visit the human race."
"Population, when unchecked, increases in a geometrical ratio."
"The means of subsistence increase in an arithmetical ratio."
"That the increase of population is necessarily limited by the means of subsistence."