Page 194

181 Doctrines: Basic Principles It might seem that the statement that the primary bodies had no weight directly contradicts the Aristotelian evidence, and that the Stobaeus text must be convicted at least of loose expression. Instead of saying that the atoms had no weight, Stobaeus should have said that their precosmic movement was not explained by their weight. But in fact the most natural understanding of Stobaeus and the Aristotelian evidence renders them consistent while allowing the former to be literally true. Weight is a tendency downwards, and its ascription is therefore relative to a spatial frame of reference, provided for us, as for the ancients, by the earth; bodies fall towards the earth, and the weight of any body is measured by the force required to resist its free fall. In the atomists' precosmic universe these conditions were absent; no frame of reference allowed the identification of 'up' and 'down' in the infinite and symmetrical void (cf. 68), nor did atoms have any tendency to move freely in any particular direction. Had the atoms all moved in parallel, as in Epicurus' precosmic universe, the direction of atomic motion could have been used to define 'down' simply as the direction of free atomic motion. But that would have been a signal violation of the Principle of Sufficient Reason; given that there was no antecedent reason for the atoms to move uniformly in one direction rather than another, the principle dictates that uniform motion should not occur, but either that atoms should move individually in all directions, or that no atom should move. It might seem that the principle requires the latter alternative, for if there is no reason for an individual atom to move in any direction rather than any other, how can it move at all? Yet motion is observed, hence the atoms must move. The difficulty is avoided by the abandonment of the conception of free motion altogether; there is always a reason for every individual atom to move in a particular direction, viz. that it is impelled in that direction by a prior atomic interaction. It is on precisely this point that Aristotle criticizes the atomists in 53, complaining that the violent motion imposed by interaction presupposes a prior, natural motion of which the atomists give no account. In reply the atomists have merely to reject the presupposition; there is in fact no requirement that motion uncaused by interaction should be prior, either logically or temporally, to motion caused by interaction, and since there was no first interaction, but an infinite succession of interactions, the question 'What motion preceded the first atomic interaction?' poses no problem. The reports in 60a and b can then be taken to be literally true; in the precosmic situation the atoms have indeed no weight. The Aristotelian evidence, on the other hand, is most naturally read as describing atoms in the context of a cosmos. What kind of downward tendency do atoms evince in that context? Here again the evidence is relatively clear and

The Atomists -- Leucippus and Democritus  

MACEDONIA is GREECE and will always be GREECE- (if they are desperate to steal a name, Monkeydonkeys suits them just fine) ΦΕΚ,ΚΚΕ,ΚΝΕ,ΚΟΜΜ...

The Atomists -- Leucippus and Democritus  

MACEDONIA is GREECE and will always be GREECE- (if they are desperate to steal a name, Monkeydonkeys suits them just fine) ΦΕΚ,ΚΚΕ,ΚΝΕ,ΚΟΜΜ...

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