... in which it is concluded against Aristotle that the existence of the purely and simply light and of the purely and simply heavy should not be assumed: which even if they were given, will not be earth and fire as he believed.</s>
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<s id="id.1.1.12.01.00"/>
<s id="id.1.1.12.01.01">Those who came before Aristotle have considered the heavy and the light only by comparison with bodies less heavy or less light; and in my opinion, this is perfectly right: now, Aristotle, in Book IV of the De Caelo, endeavours to refute the opinion of the ancients, and to confirm his own which is contrary to it.</s>
<s id="id.1.1.12.01.02">Now since in this matter we are going to follow the opinion of the ancients, we will examine Aristotle's refutations as well as his confirmations, confirming his refutations, and refuting his confirmations; and we will carry this out after we have set forth Aristotle's opinion.</s>
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<s id="id.1.1.12.02.00"/>
<s id="id.1.1.12.02.01">In the first place, then, Aristotle says, by way of definition, that he calls purely and simply heaviest that which stands under all else and is always carried towards the center; and he calls the lightest, that which rises above all else and is always moved upward, never downward: and he writes that in texts 26[311a16-18] and 31[311b16-18] of De Caelo Book IV[+308a29-31].</s>
<s id="id.1.1.12.02.02">He then says that the heaviest is earth, and the lightest is fire: and he says that in text 32 [311b19-29] and in other places.</s>
<s id="id.1.1.12.02.03">So, against those who assume a certain heaviness in fire, he argues thus: If fire has a certain heaviness, hence it will stand under something; now that is not seen; hence [etc.].</s>
<s id="id.1.1.12.02.04">This argument is not conclusive</s>
<s id="id.1.1.12.02.05">For, in order for something to hang over something else, it is sufficient for it to be less heavy than that over which it must hang; but it is not necessary that it be deprived of all heaviness; just as for wood to float on water it is not required that it necessarily be deprived of all heaviness, but it is sufficient that it be less heavy than water; and thus, by similar reasoning, for fire to hang over air, it is sufficient that it be less heavy than air, and it is not necessary that it be deprived of all heaviness.</s>
<s id="id.1.1.12.02.06">For this reason it is evident that this argument has no necessity.</s>
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<s id="id.1.1.12.03.00"/>
<s id="id.1.1.12.03.01">He also argues in the following manner: If fire has a certain heaviness, then a lot of fire will be heavier than a little bit; and for this reason a lot of fire will go up in air more slowly than a little bit of fire: and similarly, if earth has a certain lightness, a lot of earth, which will have more lightness, will go down more slowly than a little bit of earth: experience however shows the contrary; for we see that a lot of fire goes up faster than a little bit, just as also a lot of earth goes down faster: this is therefore a sign that in fire there is only lightness; and since in a lot of fire there is more lightness, it goes up faster.</s>
<s id="id.1.1.12.03.02">This argument also is weak.</s>
<s id="id.1.1.12.03.03">And, in the first place, it certainly oversteps the bounds.</s>
<s id="id.1.1.12.03.04">What follows has no value, If fire considered absolutely has heaviness, therefore </s>
