IDENTITY IS BASED ON A PARADOX. Though we carry immense histories — what Javier Marías calls “probabilities in our veins” — we can only truly know ourselves in the present. We build a self out of a past that exists as a series of stories, but we rarely stop to observe who we are in the moment. We tend to only do so at moments of great stress, and such moments are nodes into which Marías, perhaps the greatest writer working in Spanish, has peered to discover what it means to be a human.

In Marías’s work the discoveries come in three flavors. If they are sudden (a bar fight, for instance) they are ahistorical, reducing us from complex individuals with idiosyncratic histories and thick cultural milieus to flasks of reflexes. At other times (say your nation is at war) the submerged currents of history and culture come to the surface and reveal the grip they hold on our personalities. And finally, the most fraught instances occur when we tell stories about ourselves under duress and thus speak identity into being.

Marías’s ever-broadening set of narratives explores the meandering paths of these moments. He ponders: why these, and not others? How do we choose which moments constitute us — or how do they choose us — and how do we then build ourselves around them? With maximalist zeal and digressive sentences, Marías flays every last thought that goes into building identity’s superstructure while dragging his protagonists through plots that are immaculately paced and studded with one showstopper after another. His people are often intellectual loners, content on the sidelines. They are not obsessed with memory but are nonetheless dragged into their personal inquiries by exterior forces. They are almost always multicultural in the sense that they spend time outside their home nations and are comfortable in a variety of European lifestyles (of which Marías is a gifted observer).

Their adventures give Marías frequent opportunities to indulge his many fascinations: the roots of words, the long histories embedded in everyday things, the names of streets, incidental statuary, minor traditions, and overlooked works of art. To read him is to watch the various versions of European history commingle in the interactions of daily life. This is all to his point — he obsessively demonstrates how this vast “dark back of time” becomes transfigured within us. For Marías, our cultural and personal histories are never inert. No matter how distant, they are always ready to spring up into our thoughts and actions. He shows that these supposedly separate phenomena are us, much more than we realize or care to admit.

It’s uncommon to find an author who engages culture, history, and identity with Marías’s skill and depth. But what makes his fiction noteworthy is that he considers two things that are of great contemporary relevance: the lack of an agreed-upon moral authority and the unprecedented abundance of information. These things are related in a neat exchange: We have given up our moral arbiters, and in return we have received information. The loss of authority that comes with the decline of God and State gives us license to follow our tastes wherever they lead without rebuke, taboo, or punishment. Virtually any taste can be turned into a pursuit (all hail the interdisciplinary studies degree) and a libertarian streak borne of being left alone from all intr...