E2P17S
Scholium — Part II
Latin
Videmus itaque qui fieri potest ut ea quæ non sunt veluti præsentia contemplemur, ut sæpe fit. Et fieri potest ut hoc aliis de causis contingat sed mihi hic sufficit ostendisse unam per quam rem sic possim explicare ac si ipsam per veram causam ostendissem nec tamen credo me a vera longe aberrare quandoquidem omnia illa quæ sumpsi postulata, vix quicquam continent quod non constet experientia de qua nobis non licet dubitare postquam ostendimus corpus humanum prout ipsum sentimus, existere (vide corollarium post propositionem 13 hujus). Præterea (ex corollario præcedentis et corollario II propositionis 16 hujus) clare intelligimus quænam sit differentia inter ideam exempli gratia Petri quæ essentiam mentis ipsius Petri constituit et inter ideam ipsius Petri quæ in alio homine, puta in Paulo, est. Illa enim essentiam corporis ipsius Petri directe explicat nec existentiam involvit nisi quamdiu Petrus existit; hæc autem magis constitutionem corporis Pauli quam Petri naturam indicat et ideo durante illa corporis Pauli constitutione mens Pauli quamvis Petrus non existat, ipsum tamen ut sibi præsentem contemplabitur. Porro ut verba usitata retineamus, corporis humani affectiones quarum ideæ corpora externa velut nobis præsentia repræsentant, rerum imagines vocabimus tametsi rerum figuras non referunt. Et cum mens hac ratione contemplatur corpora, eandem imaginari dicemus. Atque hic ut quid sit error indicare incipiam, notetis velim mentis imaginationes in se spectatas nihil erroris continere sive mentem ex eo quod imaginatur, non errare sed tantum quatenus consideratur carere idea quæ existentiam illarum rerum quas sibi præsentes imaginatur, secludat. Nam si mens dum res non existentes ut sibi præsentes imaginatur, simul sciret res illas revera non existere, hanc sane imaginandi potentiam virtuti suæ naturæ, non vitio tribueret præsertim si hæc imaginandi facultas a sola sua natura penderet hoc est (per definitionem 7 partis I) si hæc mentis imaginandi facultas libera esset.
English (Elwes 1883)
We thus see how it comes about, as is often the case, that we regard as present many things which are not. It is possible that the same result may be brought about by other causes; but I think it suffices for me here to have indicated one possible explanation, just as well as if I had pointed out the true cause. Indeed, I do not think I am very far from the truth, for all my assumptions are based on postulates, which rest, almost without exception, on experience, that cannot be controverted by those who have shown, as we have, that the human body, as we feel it, exists (Coroll. after II. xiii.). Furthermore (II. vii. Coroll., II. xvi. Coroll. ii.), we clearly understand what is the difference between the idea, say, of Peter, which constitutes the essence of Peter's mind, and the idea of the said Peter, which is in another man, say, Paul. The former directly answers to the essence of Peter's own body, and only implies existence so long as Peter exists; the latter indicates rather the disposition of Paul's body than the nature of Peter, and, therefore, while this disposition of Paul's body lasts, Paul's mind will regard Peter as present to itself, even though he no longer exists. Further, to retain the usual phraseology, the modifications of the human body, of which the ideas represent external bodies as present to us, we will call the images of things, though they do not recall the figure of things. When the mind regards bodies in this fashion, we say that it imagines. I will here draw attention to the fact, in order to indicate where error lies, that the imaginations of the mind, looked at in themselves, do not contain error. The mind does not err in the mere act of imagining, but only in so far as it is regarded as being without the idea, which excludes the existence of such things as it imagines to be present to it. If the mind, while imagining non--existent things as present to it, is at the same time conscious that they do not really exist, this power of imagination must be set down to the efficacy of its nature, and not to a fault, especially if this faculty of imagination depend solely on its own nature--that is (I. Def. vii.), if this faculty of imagination be free.
Modern English
We can now see how it happens that we regard as present things that do not exist, as so often occurs. There may be other causes for this, but here it suffices to show one way the thing can be explained — as if its true cause had been shown. I do not think I am far from the truth, since all the postulates I relied on contain almost nothing that is not confirmed by experience, which we cannot doubt once it has been shown that the human body, as we feel it, exists (E2P13C).
From the preceding corollary (E2P17C) and from the second corollary of Proposition 16 (E2P16C2), we clearly understand the difference between the idea of Peter, for example, which constitutes the essence of Peter's own mind, and the idea of Peter that exists in another person, say Paul. The former directly expresses the essence of Peter's own body and involves existence only as long as Peter exists. The latter indicates the constitution of Paul's body more than the nature of Peter, and so, while that constitution of Paul's body persists, Paul's mind will regard Peter as present to it even though Peter no longer exists.
To retain ordinary language: the affections of the human body whose ideas represent external bodies as present to us we will call images of things, even though they do not reproduce the shapes of things. When the mind regards bodies in this way, we say it imagines.
Here, to begin indicating where error lies, note that the imaginations of the mind, considered in themselves, contain no error. The mind does not err in the mere act of imagining, but only insofar as it is regarded as lacking an idea that would exclude the existence of the things it imagines as present. For if the mind, while imagining non-existent things as present to it, at the same time knew that those things did not really exist, it would credit this power of imagining to the strength of its nature rather than to a defect, especially if this faculty of imagining depended solely on its own nature, that is (E1D7), if this faculty of imagining were free.