The American Phrenological Journal and Miscellany, Vol. 1. No. 8, May 1, 1839

Vol. I. Philadelphia, May 1, 1839. No. 8.
Phrenology is useful, because it forms the most correct basis of a system of mental philosophy.
In a previous number of this Journal (see Art. I, page 161), we entered somewhat at length upon the discussion of the above proposition. We there contrasted the merits of phrenology, as the true science of the mind , with other systems of mental philosophy, particularly Dugald Stewart’s. We pointed out several important defects which have hitherto existed in every system of mental science. We stated that all writers on the philosophy of the mind had committed the following mistakes. First, they leave out of view almost entirely all connection of the mind with the brain ; and, secondly, they make their own individual consciousness the chief and principal source of information . And that, from these two radical defects in their premises, they have fallen into numerous errors. Among others, they do not recognise all the primitive faculties of the mind ; and throughout all their writings, they confound primitive faculties of the mind with modes of activity .
Another radical defect in the systems of previous writers on mental science is, When they admit and treat of the elementary faculties of the mind, they consider them merely as existing by themselves, and disregard almost entirely the influence of combination .
This defect is similar to what would appear in that system of chemistry which should contain only a physical description of elements of matter, without saying any thing of the various substances which they form in combination. Thus the chemist might describe oxygen by itself. He might say it is a gas, colourless, heavier than common air, a supporter of combustion and animal life, and many other things equally important, interesting, and true; and if such facts were all that is known of this substance, they should be received and appreciated according to their value. But how much is added to our knowledge, when we are informed that oxygen enters into combination with almost every other element of matter? That in one combination it forms the deadly poison; in another, the refreshing cordial. That united with nitrogen in one proportion, it constitutes the air we breathe; in another, it forms the nitrous oxyde, a substance producing the most remarkable effects of exhilaration; in a third proportion, the nitrous oxyde, which, coming in contact with our lungs, produces instant death; and in a fourth, one of the most powerful agents in nature. That with hydrogen it forms the valuable substance called water; and in other various combinations, acids so valuable in the arts and all the economy of civilised life.