40
object currently present . This , in turn , necessitates the next space must be emptied for this new object to move . This process therefore occurs as an infinite sequence , which must be completed in order for the first object to move . As the ‘ last ’ object in any sequence has nowhere into which it can translate , it follows that the entire sequence of movements cannot take place , and therefore the first object cannot move . As this applies to all physical objects , it implies that movement must be an illusion , and that , according to Parmenides , we therefore cannot rely on our physical senses .
Although arguing from entirely different first principles , Eddy came to the same conclusions regarding the true nature of our physical senses , which , in her words , are merely ‘ generators of error ’ and of ‘ false beliefs .’
Other Presocratic philosophers also offered arguments supporting the idea that our senses are misleading . Zeno , the most well-known , was the originator of a number of famous paradoxes , which although interesting in and of themselves , are designed for a very specific purpose , namely , that at the very least we should treat our sense-data with caution .
The most famous of Zeno ’ s paradoxes concerns Achilles and a tortoise . Achilles was famed for his running speed , and so in a race with a tortoise he gave the animal a generous head start . One might assume that despite this , Achilles would swiftly overtake the creature , but Zeno presented an ingenious argument that this could not actually take place . He explained that when Achilles caught up with the starting position of the tortoise , it would have moved forwards . No matter how little the amount , the point is that the tortoise would still be ahead in what we will call Position 2 . The paradox becomes apparent when , a little later , Achilles reaches Position 2 ; the tortoise , of course , has moved a little further still , in other words , to Position 3 . It is now possible to see the problem Achilles faces in Zeno ’ s paradox : every time he catches up with the tortoise at a given position , it has advanced a little further ; it appears from the argument that he can never catch up with the tortoise , let alone overtake it . This is completely at odds with our senses , which seem to communicate the visual impression of Achilles rapidly overtaking his competitor and winning the race . Zeno therefore argued that our senses must be in some way mistaken .
Other Presocratics were more focussed on the nature of the physical world . In a similar manner to Pherecydes , each concluded that there is a fundamental form of matter from which all other types are created by the actions of natural processes . This foundational substance , however , differed from philosopher to philosopher . For example , Anaximander considered it to