Ludwig Wittgenstein took at least a year to design a pair of door handles for his sister’s house in Vienna. If it sounds a little strange for one of the 20th century’s great philosophers to have spent his time on a seemingly modest piece of bent-metal bars, we might also note that he spent just as long, if not longer, designing an L-shaped radiator, which folds into a corner.

His handles consisted of a simple bar with a kink on one side. I had thought that this was to do with demarcating a formal and a less formal side to the door. Actually, it was a response to needing to avoid a clash with a mullion on the home’s French windows. Yet somehow it remains such an intriguing and uncustomary asymmetry that I wonder why the two sides are not addressed in slightly different ways more often, acknowledging the particular conditions on either side of a door.

Wittgenstein left most of the architecture of the house—the spatial and structural arrangements, the plans and the sections—to Paul Engelmann, his partner in the project, which they started on in 1926, but he did seriously obsess over the details. Locksmiths and metalworkers were apparently driven nuts by his unforgiving attention to the smallest of accents (he once, famously, had a ceiling demolished and rebuilt because it had been built 30 millimeters, a little over an inch, too low).

Wittgenstein spent this extravagant amount of time on the door handles because door handles matter. In fact, their importance is out of all proportion to their scale and cost. And, although architecture is such a visual arena, it is not just about the way door handles look, but about the way they feel.

Juhani Pallasmaa, in his 1996 book The Eyes of the Skin: Architecture and the Senses, wrote that “the door handle is the handshake of the building.” It sounds, at first, a little cheesy, that anthropomorphising of architecture. But the door handle grip is the first moment our bodies engage with a house, an apartment, or a new room, and it is one of the rare occasions in which we actually touch the building. Sure, our feet are in contact with the floor, but it is remarkable how little our hands come into contact with the architecture itself.

So the door handle becomes a cipher, a meta-architecture that is required in order to embody the ideals, the ideas, and the intentions of the architect. It explains, for instance, why the Modernists were obsessed with door handles. Among the earliest, most successful and enduring of the Bauhaus designs were the handles, notably those by Walter Gropius. It is easier and quicker to design and manufacture a piece of hardware than it is to construct a building, so the handles became the trailer for the main attraction, a taste of what Modernism could do.

Gropius’s most famous handle design dates from around 1923 and, in its deceptively simple combination of a square section and a cylinder, embodies the early geometric obsessions of the Bauhaus. It announces its intent in its blend of the ergonomic, cylindrical grip and the more architectural L-shaped, square-sectioned stem, often attached to a square rather than round backplate. It was a stripped-down expression of the bigger architectural product and an emblem of its paradoxes. This was a thing that looked like a machine part engineered itself by machines—but it was not; it was a fixture designed to fit a human hand, hand-cast and hand-polished to give it the appearance of a mechanical thing.

Gropius’s handles were produced by a Berlin company called SA Loevy. Its catalog illustrated an incredible cross section of the work of the pioneers of Modernism, from Peter Behrens to Mies van der Rohe, but it also told an alternative story: not just the retrofitted narrative of the move to functionalism, but a more complex picture embracing everything from Expressionism and historical form to the machine aesthetic and the outright weird. In fact, it was that embrace of the diversity of form which inspired me and a business partner to found a hardware maker, in 2001, in an attempt to capture an emerging moment in British architecture and design in all its difference, eccentricity, and everydayness. Although I’m no longer involved in the company, the way in which those years redirected my gaze to the door handle has stuck with me.

What Gropius was doing with the lever in 1923—attempting to essentialize the architecture through the reduced medium of the handle—was nothing new. Antoni Gaudi had created surreal miniature sculptures for his buildings: strange-looking, almost inexplicable forms that fit perfectly into the hand despite their eccentric appearance. The architects of art nouveau (notably Victor Horta) had sculpted organic, whiplash forms that imbued their handles with a sense of innate movement. The architects of the Arts and Crafts Movement in Britain revived medieval and vernacular forms, while Greene and Greene in the United States employed wooden handles in a nod to Japanese style and folksy joinery. Modernist architects tended to favor the lever over the knob, seeing it as more clearly expressive of its purpose and easier to grip.

By the mid-century, the door handle had become a staple mode of mini-expression. Across continental Europe, pull and lever handles were allowed to embody a moment of sensuous, formalist pleasure, even if the buildings they led into were often rigorous and pared back. The handle became a kind of sculpture, a legitimate vehicle for tactile pleasure. In Milan in particular, handles were allowed to become little jewels of modernity. You need only look at Gio Ponti’s sleek design for a lever for the Pirelli Building to see its extruded, aerodynamic beauty, a thing stripped down to its essence and elevated to become a motif of speed and aerodynamics.

But then something unexpected happened. This flowering of diversity and creativity began to be curtailed by a late-modern impulse toward banality. The cause was, ironically, a brilliantly elemental design and a throwback to Wittgenstein’s bent bars. In Europe, it was the arrival of the “d line” lever, a simple, slender, stainless-steel handle that became an object of almost fetishistic desire from the 1980s onward, a totem for the emerging minimalist moment. In the U.S., it was a number of generic, chunky, bent and welded tubes that began to become universal, starting in the 1960s. The American versions were always a little clunkier than their European counterparts, but the idea was the same: the minimum one could possibly do.

In recent years, the proliferation of cheap, mass-manufactured designs—some imitating classic Modernist designs, others more generic, combined with the flimsy, atemporal but kind of rococo designs that now stand for kitsch and cheapness—has made the act of entrance more globalized and less intriguing.

What is most remarkable, however, is how much attention architects lavish on a building (take a typical upscale bathroom, for instance) and how little they think about the handles. They will often allow a contractor to substitute the original specification for a cheaper version with little resistance. It is only the rarest of designers now who will design something bespoke and fight for it through months of value-engineering and cost-cutting.

It’s a curious kind of economy, the compromise with this first contact, the relegation of touch into the reductive realm of the banal. The outsize influence of this small component in the building process remains somehow still unrecognized beyond the realms of luxury real estate, where these kinds of details are marketed as a mark of exclusivity. It looks like a missed opportunity.

We might also think of the vast reserves of old hardware, which is perfectly serviceable but gets scrapped along with the rest of the building in demolitions. These items already have their patina of wear and use, their histories of human contact, embedded within them. We might aspire to think more like Wittgenstein, who spent so long on his door handle design because he knew how critical it could be.