Critical theory -- from its beginnings in the work of Marx and Nietzsche -- sees the human being as a finite, material body, devoid of ontological access to the eternal or metaphysical. That means that there is no ontological, metaphysical guarantee of success for any human action -- just as there is also no guarantee of failure. Any human action can be at any moment interrupted by death.
(Boris Groys: Under the Gaze of Theory)
I'd argue that Cambridge is a writer who senses and reacts, not a writer who reasons, but she is a prime noticer of interruptions even at the end of A Humble Enterprise when she has spent her book leading up to a marriage, arranging the marriage, getting rid of oppositions to the marriage; now she begins to wonder if she should be happy because she has succeeded. "Also, however well a marriage may begin, nobody can foretell how it will eventually turn out." The marriage could go wrong, everything could go wrong, the world could explode tomorrow; Proust points out that the sun might kill us all next weekend.
People pursue their pleasures from habit without ever thinking, were etiolating and moderating influences to cease, that the proliferation of the infusoria would attain its maximum, that is to say, making a leap of many millions of leagues in a few days and passing from a cubic mili-meter to a mass a million times larger than the sun, at the same time destroying all the oxygen of the substances upon which we live, that there would no longer be any humanity or animals or earth, and, without any notion that an irremediable and quite possible catastrophe might be determined in the ether by the incessant and frantic energy hidden behind the apparent immutability of the sun, they go on with their business, without thinking of these two worlds, one too small, the other too large for them to perceive the cosmic menace which hovers around us.
How is Ada Cambridge going to stop progress, which is the book itself? Calling on "nature, who is the mother of all wisdom" she finally shuts herself up. Nature believes in marriage and nature says that marrying was the best thing the characters could do. An appeal to nature as a fixed finite authority, recognised by everybody, this is how she puts on her brakes, by becoming Rosa Praed for a minute. The spirit of finity is Praed's friend; it has to come to Cambridge, she has to summon it, for once, like a genie that will get her out of trouble.
(I'm going to modify "she doesn't reason" by saying that she does reason (she makes equations out of thoughts, "this plus this plus this") but the expectation that she will come to a conclusion perplexes her; it amazes Ruskin too, when he thinks about it --
Do you suppose I could rightly explain to you the value of a single touch on brass by Finiguerra, or on box by Bewick, unless I had grasp of the great laws of climate and country; and could trace the inherited sirocco or tramontana of thought to which the souls and bodies of the men owed their existence?
-- even though he comes to conclusions constantly and in the same book, Ariadne Florentina, calls an Indian painting "damnable" without any more reasoning than, Because it is:
Giotto or Raphael could not have made the black more resolutely black, (though the whole color of the school of Athens is kept in distinct separation from one black square in it), nor the green more unquestionably green. Yet the whole is pestilent and loathsome [...] entirely damnable art.)