| Quote #4
"Gentlemen," said Athos, "my opinion is that it is not proper to allow lackeys to have anything to do in such an affair. A secret may, by chance, be betrayed by gentlemen; but it is almost always sold by lackeys." (19.137)
For Athos, the distinction between a gentleman and a lackey is that the latter will betray secrets for money while the former may do it only by accident. It is fitting that he makes this remark since, of the four he is the most gentlemanly of all.
| Quote #5
As long as he was in the city, Planchet kept at the respectful distance he had imposed upon himself; but as soon as the road began to be more lonely and dark, he drew softly nearer, so that when they entered the Bois de Boulogne he found himself riding quite naturally side by side with his master. (24.4)
If you want to read into this, you might argue this passage illustrates that without society (the city), the two are really rather equal.
| Quote #6
"You will understand, monsieur, I thought there would be still time, if you wish, to see Monsieur de Cavois to contradict me by saying you were not yet gone. The falsehood would then lie at my door, and as I am not a gentleman, I may be allowed to lie." (25.51)
Planchet understands his social position as giving him carte blanche to tell falsehoods. However, it’s critical that he told this particular lie. This supports D’Artagnan’s later argument that Planchet is the most intelligent of the four lackeys.