The validity of empirical evidence is due to the mind-body connection. The intellect gets empirical data from the bodily senses.
The mind also knows itself, hence logic and math.
But the intellect is also connected to the will. Praxeology is the mind reflecting on the will (or the heart) as the will goes about pursuing its happiness. It’s self-knowledge generalized.
Both logic and economics then are a priori but in different ways.