The economist Michael Perelman critically examined the belief systems from which arose intellectual property rights, the field of law that commodified knowledge and information. Samuel Bowles and Herbert Gintis critically reviewed the belief systems of the theory of human capital. Knowledge, as the philosophic means to a better life, is contrasted with capitalist knowledge (as commodity and capital), produced to generate income and profit. Such commodification detaches knowledge and information from the (user) person, because, as intellectual property, they are independent, economic entities.