Original Translation of excerpt from Grevisse’s Le Bon Usage
Below is an invaluable reference for the use of the French simple past. An original translation, it is excerpted from Grevisse's Le Bon Usage— a classic grammar book that is to French what Smyth is to Ancient Greek. I refer frequently to Grevisse when formulating my own translations. This expansion on the uses of the "passé simple" stands out from others, largely thanks to its unique treatment of the metaphysical notions of duration implicated by this tense.
III. The Simple Past
(719) The simple past (past definite) expresses an action that is completely achieved at a determined moment of the past, without consideration of the contact that this action, in itself or by its consequences, may have with the present. It implicates within it neither the idea of continuity nor that of simultaneity with respect to a past action and it marks an “action-point”.
Compère le renard se MIT un jour en frais Et RETINT à dîner commère la cigogne.
Godfather fox FOUND himself one day in debt and RETAINED for dinner Godmother stork.
Je me TROUVAI l’autre jour dans une compagnie où je VIS un homme bien content de lui. Dans un quart d’heure il DÉCIDA trois questions de morale…
I FOUND myself the other day in a group where I SAW a man [who was] very pleased with himself. Within a quarter of an hour, he DECIDED upon [the answers to] three moral questions.
Je sais que l’an dernier, un jour, le douze mai, Pour sortir le matin tu CHANGEAS de coiffure.
I know that last year, one day, the twelfth of May, In order to go out in the morning you CHANGED your hair-do.
(720) The simple past can be employed as the equivalent of the present in order to express a general truth, a fact of experience, an aphorism: this is the habitual past. In this case, the verb is accompanied by some temporal determination (toujours/always, jamais/never, souvent/often, etc.) marking the general scope of the thought:
Qui ne sait se borner ne SUT jamais écrire.
[He] who knows not [how] to confine himself never KNOWS [how] to write.
Souvenez-vous bien Qu’un dîner réchauffé ne VALUT jamais rien
Remember well That a reheated dinner IS never WORTH anything
Un bienfait reproché TINT toujours lieu d’offense.
A kindness [that has been] blamed always HOLDS the place of an offense.
Remarks: 1. The simple past sometimes expresses, without meanwhile implying the idea of continuity, a fact of which the duration has been relatively long, in propositions where this duration is indicated in a precise and limited way: “He who speaks here envisions, not the duration of the action, but simply the action, reduced as a point on the line of time” : Il MARCHA trente jours, il MARCHA trente nuits/He WALKED for thirty days, he WALKED for thirty nights (Hugo)—Il FUT, pendant vingt ans qu’on l’ENTENDIT marcher, Le cavalier superbe et le puissant archer/It WAS, during twenty years, that we HEARD him walking, the superb horseman et the powerful archer (ibid.) —Il CONTEMPLA longtemps les forms magnifiques Que la nature prend dans les champs pacifiques; Il RÊVA jusqu’au soir; Tout le jour il ERRA le long de la ravine/He CONTEMPLATED for a long time magnificent forms That nature takes in pacific fields; He DREAMT until evening; All the day he WANDERED the length of the ravine (ibid.).
2.) The simple past can yet mark an action that is repeated; in this case, it expresses the pure and simple action, in an absolute manner, and seen from the present (the imperfect would present this action as though relative to another, and seen from the past). In this usage, the simple past is ordinarily accompanied by a temporal determination such as: bien des fois/many times, souvent/often, chaque fois/each time, etc. : Cent fois, dans mes reveries, je vous VIS prendre le voile, je vous ENTENDIS me dire adieu, et je ne PLEURAI point/A hundred times, in my daydreams, I SEE you take sail, I HEAR you tell me good-bye, and I do not CRY at all (L. Veuillot). —Lorsqu’un empereur les REFUSA [les gratifications] à quelques peuples ou VOULUT donner moins, ils DEVINRENT de mortels ennemis/When an emperor refuses gratuities to some people or desires to give less, they BECOME mortal enemies (Montesquieu).
3.) The simple past, of which the endings are sometimes hetroclite [irregular], produce forms too different from the [endings] of other tenses, have almost completely disappeared from the spoken language, which has been replaced by the imperfect and most of all by the past indefinite. It still survives in Normandy and in Southern France.
4.) When it consists of multiple actions, the simple past presents them as successive; this is why it convenes particularly to narration: Claire ÉCRIVIT la lettre. Mais, le soir, elle se PLAIGNIT (…) d’être fatiguée et elle MONTA dans sa chamber plus tôt qu’à l’ordinaire/Claire WROTE the letter. But, in the evening, she COMPLAINED of being tired and she CLIMBED into her room earlier than usual (J. de Lacretelle). –The imperfect, on the contrary, presents them as simultaneous, as though forming a continuous painting; this is why it [the imperfect] convenes particularly to description in the past: L’automne S’AVANÇAIT. L’herbe, chaque matin plus trempée ne SÉCHAIT plus au revers de l’orée; à la fine aube, elle ÉTAIT blanche. Les canards, sur l’eau des douves, BATTAIENT de l’aile; ils S’AGITAIENT sauvagement/ Autumn ADVANCED. The grass, each morning more soaked did not DRY anymore on the edge of the forest; at fine dawn, it WAS white. The ducks, on the water of the moats, FLAPPED their wings, they TWITCHED savagely (A. Gide).
5.) In the expression s’il en fut/if there was, we have a frozen simple past: La maîtresse, courageuse femme s’il en FUT, vint à mourir/The mistress, courageous woman if there [ever] WAS[one], just died (Renan). —Campement délicieux s’il en FUT, où nous terminons le jour dans le sentiment d’une paix antique/Delicious encampment if there [ever] WAS [one], where we finish the day in the feeling of ancient peace (P. Loti).
In this expression, the verb sometimes comes out of its state of being frozen: Un coquin s’il en EST/A rascal if there [ever] WAS [one] (Littré). –Les Chinois, hommes de réalisation s’il en EST/ The Chinese, men of achievement if there [ever] WAS any (Cl. Farrière). —Ordre impératif, s’il en AVAIT jamais ÉTÉ/A mandatory order, if there HAD ever BEEN [one] (ibid).
 These ideas of continuity and simultaneity have, in the given definition, a great importance if one wants, in comparing French to Dutch and in general to Germanic languages, to clearly distinguish the simple past with the imperfect. These two tenses of French correspond, in fact, to one single and same time, the preterit in Germanic languages: the forms je prenais, je pris, for example, translate respectively in Dutch as Ik nam, in German as Ich nahm, in English as I took.
 Compare the gnomic aorist of the Greeks, the habitual perfect of the Latins.
 NYROP, Gramm, hist., t. VI, p. 293