> The odds against humanity surviving capitalism are great, and wishful
> thinking, is a major weakness among those opposed to it. Effective
> opposition must be grounded in profound dpessimism of the intellect.
These claims may be true, but the grounds you offer in defence of it, if I'm remembering them correctly, are too negative.
These, in sharp contrast to Marx, construct capitalism undialectically as wholly negative. You don't even seem to acknowledge the development of social productive forces as in any way positive.
Marx, in contrast, repeatedly emphasizes this as one of the two main positive developments brought about by "the dialectic of negativity" at work in capitalism, the other being "the integral development of every individual producer" that creates the individual capabilities necessary to initiate the transformation into socialism.
These developments, so he claims, are an essential prerequisite for the practicability of socialism and for a social movement able to create it.
In Marx, as opposed to Gramsci, optimism of the intellect is also optimism of the will precisely because of this idea of "the dialectic of negativity." As a way of understanding the "actual facts" of capitalism, this "dialectic" has the result that "the mere critical analysis of actual facts" (as opposed to "writing receipts ... for the cook-shops of the future") is sufficient to demonstrate "socialism" as the "obligation" and "final goal" of capitalism.
An analysis in terms of this dialectic is the carrying out in relation to capitalism of the claims made in the 1843 letter to Ruge:
"Reason has always existed, but not always in a reasonable form. The critic can therefore start out from any form of theoretical and practical consciousness and from the forms peculiar to existing reality develop the true reality as its obligation and its final goal."
These claims underpin and are implicitly repeated by the 1877 claims in draft letter to the editor of the Otecestvenniye Zapisky about what Marx understood himself to have done in Capital.
"At the end of the chapter [ of Capital on primitive accumulation} the historic tendency of production is summed up thus: That it itself begets its own negation with the inexorability which governs the metamorphoses of nature; that it has itself created the elements of a new economic order, by giving the greatest impulse at once to the productive forces of social labour and to the integral development of every individual producer; that capitalist property, resting as it actually does already on a form of collective production, cannot do other than transform itself into social property. At this point I have not furnished any proof, for the good reason that this statement is itself nothing else than the short summary of long developments previously given in the chapters on capitalist production."
The real reason for pessimism (of both the intellect and the will) is that the second of the two positive developments Marx claimed could be shown to issue with necessity from the dialectic at work in capital - i.e. "the integral development of every individual producer" - has failed to materialize. Instead, what has been left intact is "superstition" and "prejudice" - "irrationality" - of sufficient degree and extent that, when combined with the development of what are immense forces of destruction as well as production, make "the odds against humanity surviving capitalism" at least significant if not great.
Ted