It is a strange feeling to look at studies for paintings that were never realised: Michelangelo’s ‘Slaves’; Tatlin’s ‘Tower’ – works in progress, preparations, fresh tinder never lit which we have come to know as the work itself. These things are synecdoches, standing for unfinished wholes just out of imaginative reach. When these works are ubiquitous, it’s not problematic – but seeing a new study for the first time, for a work that will never exist, can we read it as a finished product in itself? Is it an artifact or an artwork? The divisions are blurred.

Yet three of the five new Stanley Spencers acquired by the Fitzwilliam Museum as part of the Acceptance-In-Lieu scheme are just this: studies, oil sketches and explorations. The rougher the sketches come, the more insight they offer into the mind of the artist. Somehow his exploratory marks have a greater aura about them, a more direct connection with the man himself, than his finished products.

The loosest of these sketches is a particularly appropriate acquisition for a Cambridge museum. A study on paper, it shows a bustling construction yard – part of a scheme depicting the building of the Tower of Babel – and was intended to adorn the University Library’s walls (the commission fell through). Hod carriers (apparently painted from life in his home village, Cookham) pass masons working on classical columns; in the background a gothic arch is chiseled and adorned. One can only imagine the architectural identikit his finished tower might have resembled.

Spencer’s subject matter is an evocative blend of patriotic and pastoral Englishness, biblical tales, Great War recollection and dry-witted self-examination. Apart from this self-examination, which the Fitzwilliam already showcases in some of Spencer’s self portraits and nude double portraits, the other flavours are encapsulated in these new acquisitions. ‘Scrubbing Clothes’ finds comforting domesticity on the battlefield, while ‘Making a Red Cross’ sees soldiers, while making a recognition signal for an aircraft, accidentally assemble a George Cross in some corner of a foreign field. Two of the pictures, though, are finished articles. ‘Making Columns for The Tower of Babel’ takes a vignette from the main sketch and renders it as an isolated episode. The most touching of the set, though, is ‘John Donne Arriving in Heaven’: flatly and honestly painted, it foreshadows the work Spencer was to do setting Christ’s ministry in England’s green and pleasant land. Where else would Donne be arriving than Widbrook Common? The soft light is English and autumnal.

As a group, these paintings are quiet and understated. The Early Modern room hardly registers their arrival (a refreshing contrast to the much trumpeted Poussin acquisition). Yet not only are they worthy of looking at: they add to the museum’s already-considerable selection of Spencer’s work, making here a terrific place to get to know an underrated modern master.