John Locke, An Essay Concerning Human Understanding, Chapter XXVII, §8-9
… A relation we have in an author of great note, is sufficient to countenance the supposition of a rational parrot.
His words are: “I had a mind to know, from Prince Maurice’s own mouth, the account of a common, but much credited story, that I had heard so often from many others, of an old parrot he had in Brazil, during his government there, that spoke, and asked, and answered common questions, like a reasonable creature: so that those of his train there generally concluded it to be witchery or possession; and one of his chaplains, who lived long afterwards in Holland, would never from that time endure a parrot, but said they all had a devil in them. I had heard many particulars of this story, and as severed by people hard to be discredited, which made me ask Prince Maurice what there was of it. He said, with his usual plainness and dryness in talk, there was something true, but a great deal false of what had been reported. I desired to know of him what there was of the first. He told me short and coldly, that he had heard of such an old parrot when he had been at Brazil; and though he believed nothing of it, and it was a good way off, yet he had so much curiosity as to send for it: that it was a very great and a very old one; and when it came first into the room where the prince was, with a great many Dutchmen about him, it said presently, What a company of white men are here! They asked it, what it thought that man was, pointing to the prince. It answered, Some General or other. When they brought it close to him, he asked it, D’ou venez-vous? It answered, De Marinnan. The Prince, A qui estes-vous? The Parrot, A un Portugais. The Prince, Que fais-tu la? Parrot, Je garde les poulles. The Prince laughed, and said, Vous gardez les poulles? The Parrot answered, Oui, moi; et je scai bien faire; and made the chuck four or five times that people use to make to chickens when they call them. I set down the words of this worthy dialogue in French, just as Prince Maurice said them to me. I asked him in what language the parrot spoke, and he said in Brazilian. I asked whether he understood Brazilian; he said No, but he had taken care to have two interpreters by him, the one a Dutchman that spoke Brazilian, and the other a Brazilian that spoke Dutch; that he asked them separately and privately, and both of them agreed in telling him just the same thing that the parrot had said. I could not but tell this odd story, because it is so much out of the way, and from the first hand, and what may pass for a good one; for I dare say this Prince at least believed himself in all he told me, having ever passed for a very honest and pious man: I leave it to naturalists to reason, and to other men to believe, as they please upon it; however, it is not, perhaps, amiss to relieve or enliven a busy scene sometimes with such digressions, whether to the purpose or no.”
I have taken care that the reader should have the story at large in the author’s own words, because he seems to me not to have thought it incredible; for it cannot be imagined that so able a man as he, who had sufficiency enough to warrant all the testimonies he gives of himself, should take so much pains, in a place where it had nothing to do, to pin so close, not only on a man whom he mentions as his friend, but on a Prince in whom he acknowledges very great honesty and piety, a story which, if he himself thought incredible, he could not but also think ridiculous. The Prince, it is plain, who vouches this story, and our author, who relates it from him, both of them call this talker a parrot: and I ask any one else who thinks such a story fit to be told, whether, if this parrot, and all of its kind, had always talked, as we have a prince’s word for it this one did — whether, I say, they would not have passed for a race of rational animals; but yet, whether, for all that, they would have been allowed to be men, and not parrots? For I presume it is not the idea of a thinking or rational being alone that makes the idea of a man in most people’s sense: but of a body, so and so shaped, joined to it: and if that be the idea of a man, the same successive body not shifted all at once, must, as well as the same immaterial spirit, go to the making of the same man.
9. Personal identity. This being premised, to find wherein personal identity consists, we must consider what person stands for; — which, I think, is a thinking intelligent being, that has reason and reflection, and can consider itself as itself, the same thinking thing, in different times and places; which it does only by that consciousness which is inseparable from thinking, and, as it seems to me, essential to it: it being impossible for any one to perceive without perceiving that he does perceive.