II. To the Principal Arguments

472. As to the first principal argument [n.440], it was stated in distinction 3 of the first book [1 d.3 nn.513-517] how something can act on itself, and response was made there to this first principal argument.

473. But as to what is added in confirmation, that ‘some of the divisions of being are not compossible in anything, so these divisions are not compossible either’ [n.441] - I concede the point about these divisions [sc. act and potency] as they are opposites. But they are opposites insofar as they state modes of any being, namely insofar as ‘one and the same thing’ is in potency before it is actually a being (or a being in act) when it already is; and in this way these divisions do not belong to any one and the same being, either formally or denominatively, namely that ‘one and the same thing’ should be said to be denominated by something in some act and at the same time by the same thing in potency. However, as act is taken for active principle and potency for passive principle, which principles fall under the essence of any definable or defined thing, then they are in this way neither opposites nor divisions of being nor repugnant to any one and the same thing.

474. As to the second argument [n.442], I say first to the authority from Physics 8, namely that everything ‘that moves by knowledge’ is divided into two, one of which is mover first and the other moved first - and the reason is of this sort, that the motive power of such a mover is an organic power so that it requires not only a distinction between body and soul as between mover and moved, but requires perhaps in the body itself - where the organic power is - a moving part of the body distinct from the moved part. But it need not be like this in the case of something non-organically moving itself, because here the whole is uniform as to first act, and the whole is in potency as to second act.

475. But as to the proof of this proposition, which is taken from the beginning of Physics 7 [n.442], where is proved that ‘nothing moves itself first’ - I say that what ‘first’ means here can be understood in two ways:

In one way it is taken as it means the same as ‘according to the whole’ and is opposed to what ‘according to a part’ means. And Aristotle takes it this way in Physics 5.1.224a21-29, where he distinguishes what it is for a thing to be moved per accidens, or as a whole, and what it is for it to be moved as to a part; Aristotle also takes ‘to be moved first’ in this way in Physics 6.6.236b19-23, where he says that ‘whatever is moved first in some time is moved in any part of that time’ - and he says it frequently elsewhere.

476. In another way what I mean by ‘first’ means precise causality, in the way it is taken in Posterior Analytics 1.4.73b26-33 in the definition of the universal.

477. I say therefore that the reasoning of Aristotle at the beginning of Physics7 [n.442] does well prove that no body is moved by itself first at the same time in this double firstness:

Because if it is moved by itself first, that is, according to the whole of itself, then the motion is present in any part of it. This consequence holds from the fact that a whole, insofar as it is a mover, is homogeneous, and that ‘to be moved’ is a homogeneous passion; but a homogeneous passion is only present first in a whole by this firstness if it is present in any part of it. So the result is that if a whole is moved first in this way, then if a part of it is at rest then the whole of it is at rest.

478. But when taking the other firstness, the firstness of precise causality, if a whole is moved by itself first, then this predicate ‘to be moved’ is not removed from the whole because it is removed from something that is not the whole, nor is it removed from the whole because it is removed from something that is not any part of the whole; for if a triangle has three angles first by this firstness, not only is the predicate ‘having three angles’ not removed from it if it is removed from a quadrilateral, but it is also not removed from it because of its being removed from a part of the triangle, as from this or that angle. Therefore ‘to be moved’ is not removed from a whole in which it is first by this firstness, even if it be removed from a part of it, which part is not it; and therefore if a whole is moved first by this firstness, it does not rest on the resting of a part.

479. But the prior inference was that it is moved first by the other firstness [sc. the firstness of ‘according to the whole’, nn.477, 475]; so it is impossible for a whole to be moved first by both firstnesses at the same time [nn.477-478], because this involves a contradiction, in that a contradiction follows [sc. the contradiction that the whole would both rest and not rest on the resting of a part]. However, some whole can precisely by the one firstness [sc. the firstness of ‘according to the whole’ n.475] be moved by itself first.

480. Now in the issue at hand, I say that a heavy thing is moved by itself first in the prior way of ‘firstness’ [n.475], because it moves and is moved according to any part whatever, and moving and being moved belong to any part whatever - although not first but insofar as any part is in the whole.

481. But does it ever belong to a heavy thing ‘to be moved first downwards’ by the firstness stated in the second way [n.476]?

I say that we can in general speak of the heavy thing’s being moved downwards either as to the being moved that belongs to the whole heavy thing or as to a part of the being moved that belongs to a part of the heavy thing. And I say that just as the whole heavy thing and a part of the heavy thing are homogeneous in heaviness, so the total being moved (which is a total passion of the whole) and the partial being moved (which is a passion of a part) are ‘being moveds’ of the same nature; and just as being moved downwards is naturally - and in general - present first by the firstness of precise causality in a heavy thing generally, so the total being moved is present in the whole heavy thing by a like firstness, and the partial being moved (which is a part of the total being moved) is present in a part of the heavy thing by a like firstness.

482. Therefore the whole homogeneous heavy thing is not moved by itself first such that the ‘being moved’, as being moved is common to the whole and to any part of the whole, is present in it first according to this firstness [sc. the firstness of precise causality], because then being moved would not be removed from the whole even if it were removed from a part; however this is false because of the other firstness [sc. the firstness of ‘according to the whole’], which is necessarily going along with it, if this other firstness is posited in a homogeneous subject with respect to a homogeneous passion.

483. However, the heavy thing is also moved with this motion by the firstness of causality, namely of precise causality - and it is true that this total motion is not removed from the whole heavy thing because it is removed from anything that is not this whole heavy thing; but it is true that a part of this whole heavy thing is not moved by this total motion, and yet not for this reason is this total motion removed from the whole heavy thing.

484. If you object that at least the total motion is removed from the whole heavy thing if partial motion is removed from a part of the heavy thing - so the total motion is not present in the whole by the firstness of precise causality (for if it were thus present, in no way would it be removed from the whole because of the removal of any other predicate from the whole that is not the whole) - I reply:

I say that the whole heavy thing, insofar as it is homogeneous, is made up of like parts (and these parts are prior in some way to the whole itself), so that when these are destroyed in idea of parts the whole does not remain; thus I say that it is not unacceptable for the parts to have their own partial properties and partial motions (and to have them somehow before the whole motion belongs to the whole itself), because even the whole motion is composed of the partial motions of the parts just as the whole heavy thing is composed of parts of the heavy thing. And then I deny the assumed proposition that ‘what belongs to something first (that is, according to precise causality) is not removed from it’ because something which is not the very predicate is removed from something which is not the very subject. For this assumed proposition is universally false when the subject has a prior subject and the property a prior property; for then on the removal of the prior property from the prior subject there follows the removal of the posterior property from the posterior subject.

485. The reasoning of Aristotle, therefore [nn.477, 442], proves precisely that the whole is not moved by itself first, that is, his reasoning proves that ‘to be moved’, which is a homogeneous property, is not present in the homogeneous whole first (that is, first according to precise causality), insofar as the property is taken as homogeneous (that is, as of the same nature) in the whole quantity and in a part of the quantity - because thus it would not be removed from the whole although it were removed from a part; and this is false, because of the firstness of the whole that is entailed here by reason of precise causality. Yet Aristotle’s reasoning does not prove that, speaking about that total motion whose parts are motions of parts and about the firstness of precise causality, the whole cannot be moved by itself first; and compatible with this stands that it is moved first by another firstness (namely the firstness of the whole), taking ‘to be moved’ generally (namely as it belongs to the whole and to any part of the whole), so that in some way one needs to assume a predicate that must be present in the whole with both the latter firstness and the former.