Amadeo Bordiga was an Italian Marxist, a contributor to Communist theory, the founder of the Communist Party of Italy, a leader of the Communist International and, after World War II, leading figure of the International Communist Party.
I really thought people were probably giving Bordiga too much shit when they said he was an 'armchair communist'.
Having read most of this before putting it down in annoyance, I can confirm that's a basically correct analysis.
Bordiga says that fighting in the Spanish Civil War was opportunist and a 'betrayal of the working class' because the communist side wasn't heterogeneous, he says resistance movements to Hitler's Germany and Mussolini's Italy were opportunist and a 'betrayal of the working class' because they ended up being replaced with liberal democracies. These are clownish takes.
Bordiga also repeatedly asserts that no new analyses of society are needed, that any more theorizing is unnecessary because Marx, Engels and Lenin have already given us everything we need. This is.. naive. Marx doesn't address racial or gender based issues and their intersection with capitalism, for instance, let alone the huge changes within capitalism with the rise of, for example, the digital space. He treats Marx like a saint and Marxism like a religion, complete with religious phraseology on occasion!
The reason I give this two stars instead of one is that the basic rundown of Marxist thought which Bordiga gives in the first section of this book is a not bad introduction to Marxism.
For every bit that is an original defense of Marxism there's two that are absurdly stupid and dogmatic. See for example: dismissing any kind of United front against fascism