Priori Quotes

It is possible to demonstrate God's existence, although not a priori, yet a posteriori from some work of His more surely known to us.

I hold that the mark of a genuine idea is that its possibility can be proved, either a priori by conceiving its cause or reason, or a posteriori when experience teaches us that it is in fact in nature.

In this movement of colors I find the essence, which does not arise from a system, or an a priori theory.

We must admit with humility that, while number is purely a product of our minds, space has a reality outside our minds, so that we cannot completely prescribe its properties a priori.

Any necessary truth, whether a priori or a posteriori, could not have turned out otherwise.