In many
philosophies of
logic statements are categorized into different
logical qualities based on how they go about saying what they say. Doctrines of logical quality are an attempt to answer the question: “How many qualitatively different ways are there of saying something?”
Aristotle answers, two: you can affirm something of something or deny something of something. Since
Frege, the normal answer in the West, is only one,
assertion, but what is said, the content of the claim, can vary. For Frege asserting the
negation of a claim serves roughly the same role as denying a claim does in Aristotle. Other Western logicians such as
Kant and
Hegel answer, ultimately three; you can affirm, deny or make merely limiting affirmations, which transcend both affirmation and denial. In
Indian logic, four logical qualities have been the norm, and
Nagarjuna is sometimes interpreted as arguing for five.