Page:Ferrier's Works Volume 1 - Institutes of Metaphysic (1875 ed.).djvu/254

226PROP. VIII.———— be the other of them: and therefore the ego cannot be known to be material—or, in other word; that part of every object of cognition which is usually called the subject or oneself, cannot be known to be of the same nature with that part of every object of cognition which is usually called the object.

1. Observe, this proposition does not demonstrate that the mind cannot be material; it only proves that it cannot be known to be such. Although in the "Observations and Explanations" appended to the propositions in the first section of our science, remarks, and even conclusions, of an ontological character may be occasionally introduced, the reader is again requested to bear in mind that all that is strictly proved, or attempted to be proved, in the demonstrations, is what is to be known or not to be known—not what is, or is not.

2. This demonstration yields as its result this important law of knowledge, that intelligence, of whatever order it may be, cannot, upon any terms, know itself to be material. Show a man to himself as a material thing; take out of his brain his pineal gland, or whatever else you please, and, presenting it to him on a plate, say, That, sir, is you, your