The principle of contradiction depends on the principle of cognition (cf. 565), which is a necessary fact expressed as follows: 'The object of thought is being'. It is the principle of all principles, the law of intelligent nature, and the essence of intelligence.
The second principle is that of contradiction, derived directly from the first: 'Being and not-being cannot be thought at one and the same time'.
The third is the principle of substance: 'Accidents cannot be thought without substance'.
The fourth principle is cause: 'A new entity cannot be thought without a cause'.
Antonio Rosmini, Origin of Thought, Part III, Chapter 2, section 567.
