  This article examines the importance of graphic representations in the social
sciences, and particularly in (medieval) history, taking as its starting point
a reflection by {\'E}tienne-Jules Marey, a physiologist and pioneer of
19th-century photography and cinema. Marey believed that the visual should
replace language in many fields. Indeed, the twentieth and early twenty-first
centuries saw an exponential multiplication of visual media, particularly with
the advent of digital technology. However, this ''graphics revolution'' has not
affected all disciplines equally. Significant differences remain between
scientific fields such as astrophysics, anthropology, chemistry and medieval
history, despite their shared commitment to describing dynamic processes and
changes of state. Yet, while historians have already digitized a large part of
the cultural heritage from Antiquity to the 10th-13th centuries, exploration of
this corpus using visualizations remains limited. There is therefore untapped
potential in this field.This article begins by outlining a typology and
quantification of the past and potential roles of visual representations in
medieval history. It examines two distinct intellectual approaches: 1. the use
of visuals to support a scientific discourse (majority) and 2. the construction
of a historical discourse based on observations made from visual figures with
the aim of modeling phenomena invisible to the naked eye. The author thus
examines the use of ''images'' in medievalism, focusing on the annual volumes
of the Soci{\'e}t{\'e} des historiens m{\'e}di{\'e}vistes de l'enseignement
sup{\'e}rieur (SHMESP), up to 2006. Two other parts of the text look at the
still-rare forms of visual representation in medieval history, particularly
those with a ''heuristic vocation'', using iconographic objects, parchments,
buildings and digitized texts. The article suggests various visualization
techniques, such as network analysis, the creation of ''stemmas 2.0'' and
interactive chronologies, which could benefit the discipline. These methods
could potentially profoundly change our understanding of ancient societies, by
showing the dynamic relationships between different aspects of these societies.
One of the most important advances expected from these visual methods is a
better understanding of the patterns of development in medieval Europe, which
varied from region to region. The hypothesis is that the scarcity of heuristic
graphics in medieval history stems from the relationship with ancient documents
and the historical method based on narration and exemplarity. The article thus
questions the value of ''visual modelling'' in medieval history, and highlights
the challenges associated with the widespread adoption of this approach in the
humanities and social sciences. Finally, the text invites us to reflect on the
nature and functioning of heuristic visual devices, by comparing medieval
''images'' and contemporary scientific visuals. In both cases, the point is to
materialize the invisible in order to show something that exists beyond the
visual. The author suggests that this way of approaching visuals could play a
growing role in the decades to come, particularly in the field of data science.
