The Brothers Karamazov - Why does Dmitri use "Bernard" as an insult?

Question

"Bernard" is first mentioned in Book XI. Ivan, Chapter IV, in an exchange between Dmitri and Alyosha:

“Ethics?” asked Alyosha, wondering.

“Yes; is it a science?”

“Yes, there is such a science ... but ... I confess I can't explain to you what sort of science it is.”

“Rakitin knows. Rakitin knows a lot, damn him! He's not going to be a monk. He means to go to Petersburg. There he'll go in for criticism of an elevating tendency. Who knows, he may be of use and make his own career, too. Ough! they are first-rate, these people, at making a career! Damn ethics, I am done for, Alexey, I am, you man of God! I love you more than any one. It makes my heart yearn to look at you. Who was Karl Bernard?”

“Karl Bernard?” Alyosha was surprised again.

“No, not Karl. Stay, I made a mistake. Claude Bernard. What was he? Chemist or what?”

“He must be a savant,” answered Alyosha; “but I confess I can't tell you much about him, either. I've heard of him as a savant, but what sort I don't know.”

“Well, damn him, then! I don't know either,” swore Mitya. “A scoundrel of some sort, most likely. They are all scoundrels. And Rakitin will make his way. Rakitin will get on anywhere; he is another Bernard. Ugh, these Bernards! They are all over the place.”

"Bernard" is then used throughout the rest of book as a insult by Dmitri. For example:

Book XI, Chapter IV

What's the use of the counsel? I told him all about it. He's a soft, city-bred rogue—a Bernard! But he doesn't believe me—not a bit of it.

Book XII, Chapter II

Since I've been arrested, he has borrowed money from me! He is a contemptible Bernard and opportunist, and he doesn't believe in God; he took the bishop in!

What's the significance of using "Bernard" as an insult?

Answer 1

After the first mention of Claude Bernard, Mitya uses him as a sort of personalised synecdoche for the worldview that he feels such scientists represent, the conquest of religion by science.

The word "Bernard" appears 13 times in the text of The Brothers Karamazov. Most of them are already quoted in your question, and the others shed no further light on the meaning of the term as used by Mitya, being just further reminders that he uses the term without anyone understanding what he means by it.

He sees "savants" such as chemists as "all scoundrels", and nowadays "all over the place", but why? His thought process may be revealed by another quote from Mitya in Book XI, Chapter IV (emphasis mine):

“That I am sorry to lose God? It's chemistry, brother, chemistry! There's no help for it, your reverence, you must make way for chemistry. And Rakitin does dislike God. Ough! doesn't he dislike Him! That's the sore point with all of them. But they conceal it. They tell lies. They pretend. ‘Will you preach this in your reviews?’ I asked him. ‘Oh, well, if I did it openly, they won't let it through,’ he said. He laughed. ‘But what will become of men then?’ I asked him, ‘without God and immortal life? All things are lawful then, they can do what they like?’ ‘Didn't you know?’ he said laughing, ‘a clever man can do what he likes,’ he said. ‘A clever man knows his way about, but you've put your foot in it, committing a murder, and now you are rotting in prison.’ He says that to my face! A regular pig! I used to kick such people out, but now I listen to them. He talks a lot of sense, too. Writes well. He began reading me an article last week. I copied out three lines of it. Wait a minute. Here it is.”

God is also mentioned in the passage that you quote from Book XII, Chapter II (emphasis mine):

“Since I've been arrested, he has borrowed money from me! He is a contemptible Bernard and opportunist, and he doesn't believe in God; he took the bishop in!”

It seems from these lines that Mitya sees scientific advances, such as those made by Claude Bernard, to be a threat to God and religion. Without context, it's impossible to make the connection between this worldview and the word "Bernard", which is why other characters are mystified by his references to "Bernards". But the reader, unlike most of the characters, has the advantage of having seen Mitya's exchange with Alyosha where Bernard is first mentioned.