At the foundation of the judgments which express the types of synthetic combination, through which knowledge is possible, lie the pure general notions, the abstract aspect of the conditions under which objects are cognizable in experience.
Sense had been assumed as furnishing the particular of knowledge, understanding as furnishing the universal; and it had been expressly declared that the particular was cognizable only in and through the universal.
Our knowledge is relative," said he, " first, because existence is not cognizable absolutely and in itself, but only in special modes; second, because these modes thus relative to our faculties are presented to and known by the mind, only under modification, determined by these faculties themselves."
It is therefore as unalterable, even by God himself, as the truths of mathematics, although its effect may be overruled in any particular case by an express command of God; hence it is cognizable a priori, from the abstract consideration of human nature, though its existence may be known a posteriori also from its universal acceptance in human societies.
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.