[Phys-l] Fwd: Weight vs mass

[jbellina <jbellina@SAINTMARYS.EDU>]

Here is the third response on the history of weight vs mass...you may  
need some French.

joe

Joseph J. Bellina, Jr. Ph.D.
Professor of Physics
Saint Mary's College
Notre Dame, IN 46556

Begin forwarded message:

> From: Georges Moyal <Moyal@glendon.yorku.ca>
> Date: October 24, 2006 10:11:10 AM EDT
> To: Joseph Bellina <jbellina@SAINTMARYS.EDU>
> Subject: Weight vs mass
>
> Dear Profesor Bellina,
>
> Sorry for being somewhat late in answering your query.
> There are a number of passages in Descartes which show that he  
> views weight
> as what Locke would call "secondary qualities" (like colour, smell,  
> etc.) :
> in one passage he maintains that it is a "relative" property, by  
> which he
> means that a body acquires weight only by being in the presence of  
> another
> body; it is not an inherent property of it as its size, shape, etc.  
> would
> be. I have pasted the following passages culled from the Ch. Adam & P.
> Tannery ("AT") edition of his works (the standard reference). They  
> are in
> French, but the references should help you (or your colleague) through
> available translations in English. I am not sure, however, that one  
> would
> find the notion of mass in Descartes; he may well have been content  
> with
> that of size instead.
> I hope this is of some help.
> Incidentally, I am also not sure whether he is the first to have  
> held this
> position: Galileo (who holds similar views on secondary qualities and
> might well include weight among them) may be worth having a look at.
>
> 1.À Mersenne [?] automne 1635 (AT I, 324) : « ?je ne crois point  
> non plus
> que les corps pesants descendent par quelque qualité réelle, nommée
> pesanteur, telle que les philosophes l'imaginent, ni aussi par quelque
> attraction de la terre ; »
>    Cf. Principes IV, art. 202 et Corresp. AT IV, 716.
>
> 2. Corresp. À ***** (sans date ; AT IV, 716) : « Défiez-vous de deux
> préjugés, à savoir qu'il peut y avoir du vide, et que la force qui  
> fait
> qu'une pierre tend en bas, qu'on nomme sa pesanteur, demeure  
> toujours égale
> dans la pierre ; qui sont choses qu'on imagine communément comme
> véritables, quoiqu'elles soient très fausses. »
>    Cf. Principes IV, art. 202 et Corresp. AT I, 324.
>
> 3. Principes IV, 202 (AT XI, 320) : « ?il [Arist.] leur attribuait  
> de la
> pesanteur, et moi je nie qu'il y en ait en aucun corps, en tant  
> qu'il est
> considéré seul, pour ce que c'est une qualité qui dépend du mutuel  
> rapport
> que plusieurs corps ont les uns aux autres? »
>    Cf. Corresp. AT I, 324 et IV, 716.
>
>    Georges J. D. Moyal
>    c/o Dept of Philosophy,
>    Glendon College / York University,
>    2275, Bayview Ave.,
>    Toronto, Ont., M4N 3M6
>    Canada