 Al-Fārābī in a small treatise on the void took a similar approach, but now from the direction of what is meant by ‘body’ (al-Fārābī 1951). He begins by considering an experiment that might lead one to conclude that a void exists. The experiment involves sucking air out of a vial and then placing one’s finger on the mouth of the vial. One next inverts the vial into a bowl of water and then removes the finger from the mouth of the vial. A certain amount of water will be attracted into the vial, and so one might conclude that a void space proportional to the amount of water drawn into the vial was present while one’s finger was over the mouth of the vial. The conclusion does not follow, argued al-Fārābī; for he believed that one must concede that the purported void space in the vial has a certain volume, but since volume just is a body possessing length, breadth and depth, there must be a body in the purported void  space.[8]  In this respect al-Fārābī was simply following the standard definition of ‘body’ as whatever possesses three dimensions; however, he also suggested that there is something incoherent about considering void as some sort of absolute nothingness possessing three dimensions, since there is no coherent sense in which nothingness could be the subject for the accidental qualities of length, breadth and  depth.[9]  Given these considerations against the void, continued al-Fārābī, one should conclude from the above experiment that the volume of air expanded, and consequently a smaller amount of air now occupies the same amount of space. In other words, the particular volume that a body possesses, and particularly in the case or air, is not essential to that body, and so given the right causal factors or conditions a body’s volume can expand or decrease. Al-Fārābī’s suggestion here was to become the standard among Arabic-speaking natural philosophers when dealing with purportedly artificially manufactured voids.