Excerpted from Dux Dubitantiam 2.40

Proposition 25: The principles of a single composite substance are matter and form. And in every way it lacks a mover-operator which would move the matter, until it is ready to receive form. And this is the proximate mover which is the preparer of the single matter. And this requires a consideration about motion, and the mover, and the thing moved. It has, therefore, has already been shown in all these things what must be demonstrated. Moreover, the words of Aristotle [indicate] that matter does not move itself. Moreover this is a strong proposition which leads us to an inquiry about the prime mover. Therefore, of those 25 propositions, some are proved by easy consideration with probable propositions and by reference the first intelligible [principles] or those which are like them; some need many proofs and propositions. However, all have already been proved with proofs in which there is no doubt, partly in the book "On natural hearing" and its explanations, partly in the "Metaphysics" and its exposition. But I have already let you know that it is not our intention in this book to transmit the words of the philosophers, but to demonstrate propositions, proximate and remote -- namely those which we need for the purpose of the argument in which we are [involved].

original latin

Ex propositione vigesima quinta sequitur quod motor est qui movet materiam generabilium et corruptibilium donec recipiat formam. Cum vero quaesiverimus de isto motore propinquo quo moverit ipsam. Siquidem quatuor sunt genera: sicut praemissum est in propositione quarta. Et hic non procedit in infinitum: sicut dicitur in propositione tertia. Invenimus autem quod omnis motus pervenit usque ad motum corporis quinti: et ibi statur nec procedit ultra.

Et ex illo motu provenit omne mobile. Et ex eo pendet omnis motor, et omnis compositor in mundo inferiori. Coelum vero movet motu locali qui est antiquus et primus: sicut diximus in propositione xiiii. Sic etiam omnis motus localis pervenit usque ad motum coeli.

Verbi gratia lapidem motum movit baculus motus a manu, quam moverunt chorde brachii, quas movent nervi qui sunt in musculis, quos moverunt alii nervi moti a calore naturali quem movet forma ipsius qui est motor primus.

Si ergo demonstratum est quod primus motor coeli, si motus eius fuerit sempiternus, de necessitate nec est corpus nec potentia in corpore ullo modo, nisi sit in eo motus substantialis, vel accidentalis, et ideo non est portibilis vel mutabilis ullo modo, sicut dictum est in propositione quinta et septima. Hic autem motor est Creator benedictus scilicet causa prima motus coeli.