"Look at us, Aramis! We are three out of the four. You are deceiving me, I suspect you, and Porthos sleeps; an admirable trio of friends, don't you think so?- a beautiful relic!" (14.78)
Despite the rifts in their relationship indicated by this passage, the friends actually remain deeply loyal to each other.
"A friend's word is the truth itself. If I think of touching, even with one finger, the son of Anne of Austria, the true King of this realm of France; if I have not the firm intention of prostrating myself before his throne; if, according to my wishes, to-morrow here at Vaux will not be the most glorious day my King ever enjoyed,- may Heaven's lightning blast me where I stand!" Aramis had pronounced these words with his face turned towards the alcove of his bedroom, where d'Artagnan, seated with his back towards the alcove, could not suspect that any one was lying concealed. The earnestness of his words, the studied slowness with which he pronounced them, the solemnity of his oath, gave the Musketeer the most complete satisfaction. (14.104)
Aramis does indeed feel loyalty to Philippe.
"Yes, Monsieur, we both love him, but each in a different manner," replied La Valliere, with such an accent that the heart of the young King was powerfully affected by it. "I love him so deeply that the whole world is aware of it, so purely that the King himself does not doubt my love. He is my King and my master; I am the humblest of his servants. But he who touches his honor touches my life. Now, I repeat that they dishonor the King who advise him to arrest M. Fouquet under his own roof." (15.35)
La Valliere is probably the only person close to the King who is completely free of any personal or political agenda – she really does love the King and wants what's best for him. One could say she is the only person in King Louis's court who is truly loyal.
"Warn the Prince, and then- do what? Take him with me? Carry this accusing witness about with me everywhere? War, too, would follow,- civil war, implacable in its nature! And without any resource- alas, it is impossible! What will he do without me? Without me he will be utterly destroyed! Yet who knows? let destiny be fulfilled! Condemned he was, let him remain so, then! (21.231)
Clearly Aramis feels no real loyalty to Prince Philippe.
"Yes, and leave Porthos behind me, to talk and relate the whole affair to every one,- Porthos, who will suffer, perhaps! I will not let poor Porthos suffer. He is one of the members of my own frame; his grief is mine. Porthos shall leave with me, and shall follow my destiny. It must be so." (21.231)
This demonstrates Aramis's loyalty to Porthos.
"You are not gone, then?" cried he. "Oh, Monsieur! the true King in loyalty, in heart, in soul, is not Louis of the Louvre or Philippe of Ste. Marguerite; it is you, the proscribed, the condemned!" (40.47)
Fouquet has demonstrated time and again that he is truly a great, honorable, and loyal man.
"Hush, Messieurs! you disturb the King."
"All is over!" said he; "the Musketeers of the present day are not those of his Majesty Louis XIII. All is over!" (52.72 – 52.74)
This is a sign that the Musketeers of the present day lack the type of loyalty to their captain that the Musketeers of yesteryear possessed.
"Great they will be, I feel; but if by chance I should not think them so? I have seen war, Sire; I have seen peace; I have served Richelieu and Mazarin; I have been scorched with your father at the fire of Rochelle, riddled with thrusts like a sieve, having made a new skin ten times, as serpents do. After affronts and injustices, I have a command which was formerly something, because it gave the bearer the right of speaking as he liked to his King." (53.64)
Although D'Artagnan's loyalties to the King are unquestionable, he has also expected to retain the right to question his sovereign.