ciple be intrinsecal, we shall not perceive a local motion that is derived from our selves, and we shall never discover a propension perpetually annexed to our selves.
Salv.So that the instance of this Philosopher lays its stress upon this, that whether the principle by which we move round with the Earth be either extern, or intern, yet however we must perceive it, and not perceiving it, it is neither the one nor the other, and therefore we move not, nor consequently the Earth. Now I say,Our motion may be either interne or externe, and yet we never perceive or feel it. that it may be both ways, and yet we not perceive the same. And that it may be external, the experiment of the boat superabundantly satisfieth me; I say, superabundantly, because it being in our power at all times to make it move, and also to make it stand still, and with great exactness to make observation, whether by some diversity that may be comprehended by the sense of feeling, we can come to know whether it moveth or no, seeing that as yet no such science is obtained: Will it then be any matter of wonder, if the same accident is unknown to us on the Earth, the which may have carried us about perpetually, and we, without our being ever able to experiment its rest?The motion of a Boat insensible to those that are with in it, as to the sense of feeling. You, Simplicius, as I believe, have gone by boat many times to Padoua, and if you will confess the truth, you never felt in your self the participation of that motion, unless when the boat running a-ground, or encountring some obstacle, did stop, and that you with the other Passengers being taken on a sudden, were with danger over-set. It would be necessary that the Terrestrial Globe should meet with some rub that might arrest it, for I assure you, that then you would discern the impulse residing in you, when it should toss you up towards the Stars. It's true, that by the other senses, but yet assisted by Reason,The boats motion is perceptible to the sight joyn'd with reason. you may perceive the motion of the boat, that is, with the sight, in that you see the trees and buildings placed on the shoar, which being separated from the boat, seem to move the contrary way.The terrestrial motion collected from the stars. But if you would by such an experiment receive intire satisfaction in this business of the Terrestrial motion, look on the stars, which upon this reason seem to move the contrary way. As to the wondering that we should not feel such a principle, supposing it to be internal, is a less reasonable conceit; for if we do not feel such a one, that cometh to us from without, and that frequently goeth away, with what reason can we expect to feel it, if it immutably and continually resides in us? Now let us see what you have farther to allege on this argument.
Simpl.Take this short exclamation. Ex hac itaque opinione necesse est diffidere nostris sensibus, ut penitùs fallacibus vel stupidis in sensilibus, etiam conjunctissimis, dijudicandis. Quam ergò veritatem sperare possumus à facultate adeò fallaci ortum trahentem? [Which I render thus:] From this opinion likewise, we must ofnecessity
