Page:An Essay on the Principle of Population (1798).djvu/195

Rh made, and is making, a decided progress towards an illimitable extent of life. And the chief reason why I adduced the two particular instances from animals and plants, was to expose, and illustrate, if I could, the fallacy of that argument, which infers an unlimited progress, merely because some partial improvement has taken place, and that the limit of this improvement cannot be precisely ascertained.

The capacity of improvement in plants and animals, to a certain degree, no person can possibly doubt. A clear and decided progress has already been made; and yet, I think it appears, that it would be highly absurd to say, that this progress has no limits. In human life, though there are great variations from different causes, it may be doubted, whether, since the world began, any Rh