马尔萨斯认为，只要允许世界的人口继续不受限制，乌托邦社会就永远无法实现。保护地球并改善人类的存在的唯一方法是，他认为大自然最终将以广泛的饥荒和疾病的形式提供的人类少了。
(Malthus believed that a Utopian society could never be achieved as long as the world's population was allowed to continue to grow unchecked. The only way to protect the earth and improve the existence of mankind was to have less of mankind-something he believed Mother Nature would eventually deliver in the form of widespread famine and disease.)