Learn English – What does “tipped” mean in this sentence

When one has a cold, with a stopped-up nose, the letters m and n (and v and others) are not nasalized and so come out as b or d or other sounds. Nasalized, non-stopped phonemes can get dropped entirely, like the l in the following sentence.

I hab a co'd so I ca't talk. [I have a cold so I can't talk.]

In the following sentence, the n becomes a d and the m sounds turn into b sounds:

Whed are you beeting be for breakfast? [When are you meeting me for breakfast.]

And so on.

According to Wikipedia,

Moral luck describes circumstances whereby a moral agent is assigned moral blame or praise for an action or its consequences even though it is clear that said agent did not have full control over either the action or its consequences.

More simply, it is the idea that people are to be held responsible for an action even when they aren't the only force that caused it - even if it occurred accidentally.

This stands a bit in contrast to the typical sentiment that responsibility correlates with voluntary action. (Meaning, if you choose to do something and do it, you are responsible for it.)

There are some interesting problematic examples in the Wikipedia article you might want to check out.

I don't know enough about Gauguin to speculate as to why he's such a good example of moral luck, but hopefully knowledge of the term will make the book's argument clearer in context.