"They were the best parts of life, its secret truth, its hidden reality. They had a gorgeous virility, the charm of vagueness, they passed before him with a heroic tread [...]" (3.4)
Jim's talking about his "imaginary achievements" (3.4) here, which are all about being virile and heroic. But they're imaginary, and we'll soon find that Jim's reality doesn't live up to his dreams.
"He was of the right sort; he was one of us. He talked soberly, with a sort of composed unreserve, and with a quiet bearing that might have been the outcome of manly self-control, of impudence, of callousness, of a colossal unconsciousness, of a gigantic deception. Who can tell?" (7.1)
Marlow is pointing out a huge flaw in the "system." He's part of an exclusive club of sorts – a community of gentlemen sailors, and the criteria for belonging to this club are pretty straightforward: be a sailor, be a gentleman (i.e. middle class), and be well-behaved. Marlow declares that Jim is "one of us," because he fits the bill. But Jim could also be a "deception," which means that membership criteria to the club just might need to be reconsidered. At the very least, Jim's membership should be revoked.
"I can't tell you whether Jim knew he was especially "fancied" but the tone of his references to 'my Dad' was calculated to give me a notion that the good old rural dean was about the finest man that ever had been worried by the cares of a large family since the beginning of the world." (7.6)
This book isn't full of positive examples of masculinity, but Jim's dad is one of them. But is Jim's dad only able to be as good as he is because he's safely tucked away in rural England and not exposed to the dangers and choices out in the empire? The book poses this question several times.
"'There is a kind of courage in facing it out as he does, knowing very well that if he went away nobody would trouble to run after him.' 'Courage be hanged!' growled Brierly. 'That sort of courage is of no use to keep a man straight, and I don't care a snap for such courage.'" (6.13)
Brierly and Marlow have very different ideas of what a man's duty is. Marlow finds Jim's courage in standing trial admirable, but Brierly calls it worthless. Brierly's protest is a bit confusing, but his diction helps reveal what he might mean. He uses the word "straight" which implies that Jim's decision to stand trial is making things crooked and confused. Brierly's notions of proper manly behavior seem to center around keeping things simple and maintaining the status quo. By standing trial and exposing his failure to the world, Jim is giving a sailors a bad name.
"'We aren't an organized body of men, and the only thing that holds us together is just the name for that kind of decency. Such an affair destroys one's confidence. A man may go pretty near through his whole sea-life without any call to show a stiff upper lip. But when the call comes ...'" (6.14)
... you had better show it. (Brierly was trailing off, so we thought we'd just finish his thought for him.) This quote reveals why the <em>Patna</em> scandal has so gotten under Captain B's skin: Jim has violated the one thing that binds sailors together: a sense of decency.
"'You ain't going to hit a chap with a broken arm – and you call yourself a gentleman, too.'" (10.12)
Jim's status as a "gentleman" works against him here. The sailors who jump from the <em>Patna</em> with him are all lower class, and they consistently abuse and mock Jim for his social standing.
"[T]here was a villainy of circumstances that cut these men off more completely from the rest of mankind, whose ideal of conduct had never undergone the trial of a fiendish and appalling joke." (10.20)
The <em>Patna</em> incident is a trial by fire that reveals unpleasant truths to all involved. Mostly it reveals their inner characters, which turn out to be pretty darn unappealing.
"The real significance of crime is in its being a breach of faith with the rest of mankind, and from that point of view he was no mean traitor, but his execution was a hole-and-corner affair." (14.1)
Jim didn't exactly act in "breach of faith" with all of mankind (just the sailor portion), but for the purposes of Marlow and Co. it's as if he did. Oh, and by the way, "hole-and-corner" is an old-fashioned way of saying secretive.
"Such wandering corpses are common enough in the North Atlantic, which is haunted by all the terrors of the sea [...] and one feels like the empty shell of a man." (14.3)
These men can be as manly as they want, but facing the scary power of the sea, they're nothing but empty shells.
"Had he been a girl – my friend wrote – one would have said he was blooming – blooming modestly – like a violet, not like some of these blatant tropical flowers." (18.1)
It's striking how often Jim is compared to a girl in the novel. He's described as being shy, blushing, attractive to the point of pretty, demure. These comparisons tell us a lot about how gender was viewed at the time: men were manly and girls were girly, and there was supposed to be a very rigid distinction between the two. But because Jim has acted in an unmanly way, he'll have to suffer the unflatteringly feminine descriptions.