In some Rishonim like Ibn Pakuda [חובות הלבבות], Binyamin the Doctor [author of מעלות המידות] and the Rambam we find an emphasis on Physics and Meta-Physics. [And they mean these subjects as understood by the ancient Greeks as the Rambam states openly in the Introduction to the Guide.] So what is included in these? I think Physics is clear. But Metaphysics is less clear. Certainly as the Rishonim understood these include Plato, Aristotle, Plotinus. But what of later authors? I suggest Kant, Hegel, Leonard Nelson.
[I know that there is an argument between the Kant Fries School of Leonard Nelson and Hegel, and I have no resolution to this problem. Both schools of thought have some important points.]
The basic way that one can resolve the approach of Jacob Fries with Hegel is that of dynamics. While to Fries there is an exact limit to reason that never change, and to Hegel there is no such limit, one can see that this limit can expand. [It can be dynamic. It moves.]
