References
- Hume , David . 1739–40 . A Treatise of Human Nature
- Edney , Clarence W. 1948 . “George Campbell's Theory of Logical Truth” . Speech Monographs , XV : 28
- Russell , Bertrand . 1913 . The Problems of Philosophy London
- Whately , Richard . 1846 . Elements of Rhetoric , 7th ed. rev. London