Two architects, two different practices. One specialises in luxurious mega-projects and planetary – interplanetary! – ambition: skyscrapers, hub airports, spaceports. The other delivers modest, resourceful, community-based projects, some of which are left to the residents to finish.

Two architects, two different visions for architecture. One speaks of its revolutionary, transformational potential, urging architects to grasp some of the most difficult and pervasive problems of our age. The other is limited and pragmatic, and says that architects don't really have the ability to change anything.

Can you match the practice to the vision? It's a trick question, of course. It's Lord Foster, whose practice now works on the scale of city-region, nation-state and near-earth orbit, who presents the starkest view of architecture's scope for effecting change. "I have no power as an architect, none whatsoever," he told the Observer's Rowan Moore in a searching interview published on Sunday. "I can't even go to a building site and tell people what to do."

Over at the Guardian, however, Chilean architect Alejandro Aravena – director of the 2016 Venice Biennale – calls for architects to break out of their disciplinary boundaries and engage with issues such as "immigration, water, land capacity, waste and so on."

"We want to understand what design tools are needed to subvert the forces that privilege individual gain over collective benefit," he writes, launching his ambitions for the biennale; "to highlight cases that resist reductionism and oversimplification, and do not give up on architecture's mission to penetrate the mystery of the human condition."

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"[R]epeatable formulas make most of the space in the world," wrote the theorist Keller Easterling in her magnificent essay "The Action is the Form" (Strelka Press, 2012). "These buildings are not singularly crafted enclosures but reproducible products – spatial products. The discipline of architecture is only responsible for a trickle of the world's spaces while a fire hose blasts out the rest… Architecture is making the occasional stone in the water. The world is making the water."

Aravena calls for a rethinking of the role of the architect, and new language to express that role. What could we call the new, expanded, discipline that Foster and Aravena both appear to have in mind? Perhaps we don't need a word for it at all – it's architecture, behaving as architecture should.

What might be needed is a word to describe the side of the practice that doesn't aspire to these broader, more important goals. The side that mostly only exists to give a sheen of design to routine neoliberal spatial products. Architecture as surface and appearance, architecture that is camouflage and alibi. This slippery stuff, which feels like architecture but isn't, could be called architexture.1

In a world filled with architexture, it's pleasing to see architects examining their purpose, and finding the edge and role of the real thing.

• 1. Will Wiles is the author of two novels with architectural themes: Care of Wooden Floors, in which a man is driven mad by a minimalist apartment, and The Way Inn, a horror story set in an anonymous chain hotel. He is contributing editor at Icon magazine and a freelance design journalist.