  One example of the way that Crescas uses this new definition is to refute the proofs of Aristotle against the existence of infinity. In Aristotle’s opinion, two bodies cannot share the same space because of the property of dimension. The Greek philosopher concludes from this observation the impossibility of the existence of a void. The definition of a void is dimensional space without matter inside. Now if matter can fill a void, and matter itself has dimensions, then it follows that the dimensions of the matter can go inside the dimensions of the void. Aristotle concludes that this cannot be, for if dimensions can be shared, then we have to assume that two physical bodies could be in the same place at the same time — an absurdity that would lead to other apparent absurdities, such as the entire world fitting inside a grain of mustard.