Certitude: An Attempt to Clarify...Part Three

Modernist Agnosticism is a far cry from the absolute certitudes taught by the Church as in the philosophical theology of St. Thomas Aquinas (d.1274).  According to the teaching of the Church from the beginning, the truths of faith are absolutely certain; and the scholastics developed the theology of the natural order from both Plato and Aristotle, according to which the first principles of reason are also absolutely certain.  In brief, these first principles are:

1.  The intellect's affirmative judgment that things exist outside the mind
2.  The principle of identity based on its essence, i.e., what it is as opposed to that it is
3.  A thing cannot be (exist) or not be, at the same time in the same manner.  This principle of contradiction (or non-contradiction) depends upon the two former principles of existence and essence. 
4. The principle of sufficient reason leads directly to the four causes:  efficient and final; material and formal.

The principles according to substance and accidents proceed directly from all three of the former principles.  The absolute certitude of these principles is affirmed by the Oath Against Modernism and the Twenty-Four Theses of Scholastic Philosophy, all of which were issued by and mandated under Pope St. Pius X (d.1914).