Hume's analysis of the conceptions of a permanent world and a permanent self reduces us to the sensationalistic relativism of Protagoras.
The problems raised by the relativism of Protagoras are no less fundamentally problems of the nature of knowledge and of the structure of thought.
The relativism or phenomenalism which Hamilton afterwards adopted from Kant and sought to engraft upon Scottish philosophy is wholly absent from the original Scottish doctrine.
Thus scepticism and relativism are superseded by a historical philosophy, and the absoluteness of truth is affirmed, but the notion of a definite truth is at the same time both negated and satirized.
These distinctions, he insists, have an objective reality, The cognizable by reason no less than the relations of Cambridge space or number; and he endeavours to refute moralists, Hobbism - which he treats as a " novantique philo- C d sophy," a mere revival of the relativism of Protagoras - chiefly by the following argumentum ad hominem.