Tuesday, August 18, 2009

Q115 A1: Whether a body can be active?

Yes. Some bodies are active because it is apparent to the senses.

Corpora sunt activa quia sensibiliter apparet.

A body is composed of potentiality and act; and therefore it is both active and passive.

Corpus autem componitur ex potentia et actu, et ideo est agens et patiens.

We must therefore say that a body acts inasmuch as it is in act, on a body inasmuch as it is in potentiality.

Dicendum est ergo quod corpus agit secundum quod est actu, in aliud corpus secundum quod est in potentia.

Action is not effected by local movement, as Democritus held, but by something being reduced from potentiality to act.

Actio non fit per motum localem, ut Democritus posuit, sed per hoc quod aliquid reducitur de potentia in actum.

To act, which is nothing else than to make something to be in act, is essentially proper to an act as such; wherefore every agent produces its like. So therefore to the fact of its being a form not determined by matter subject to quantity, a thing owes its being an agent indeterminate and universal: but to the fact that it is determined to this matter, it owes its being an agent limited and particular.

Agere autem, quod nihil est aliud quam facere aliquid actu, est per se proprium actus, inquantum est actus, unde et omne agens agit sibi simile. Sic ergo ex hoc quod aliquid est forma non determinata per materiam quantitati subiectam, habet quod sit agens indeterminatum et universale, ex hoc vero quod est determinata ad hanc materiam, habet quod sit agens contractum et particulare.

Wherefore if the form of fire were separate, as the Platonists supposed, it would be, in a fashion, the cause of every ignition. But this form of fire which is in this corporeal matter, is the cause of this ignition which passes from this body into that. Hence such an action is effected by the contact of two bodies.

Unde si esset forma ignis separata, ut Platonici posuerunt, esset aliquo modo causa omnis ignitionis. Sed haec forma ignis quae est in hac materia corporali, est causa huius ignitionis quae est ab hoc corpore in hoc corpus. Unde et fit talis actio per contactum duorum corporum.


The term of a body's action is both an accidental form and a substantial form. For the active quality, such as heat, although itself an accident, acts nevertheless by virtue of the substantial form, as its instrument: wherefore its action can terminate in a substantial form.

Corpus agit et ad formam accidentalem, et ad formam substantialem. Qualitas enim activa, ut calor, etsi sit accidens, agit tamen in virtute formae substantialis, sicut eius instrumentum; et ideo potest agere ad formam substantialem.

A body is not that which is most distant from God; for it participates something of a likeness to the Divine Being, inasmuch as it has a form. That which is most distant from God is primary matter; which is in no way active, since it is a pure potentiality.

Corpus non est id quod maxime distat a Deo, participat enim aliquid de similitudine divini esse, secundum formam quam habet. Sed id quod maxime distat a Deo, est materia prima; quae nullo modo est agens, cum sit in potentia tantum.