Modernity, from its origins, has accorded a key role to passions. Whether hostile to Reason or, on the contrary, favourable towards it, passions are dangerous and fascinating and bring out the role of the body, desire, language and the imagination in human nature. The same period has witnessed the development of different variants of materialism. Almost all of them re-evaluate what Classical Reason tended to suppress or consider as an indicator of human weakness, namely the body and everything which, in the soul or in society, bears the traces of bodily activity and body positivity.
One might, therefore, expect materialists to accord particular significance to passions, to recognise laws within them rather than just defects and vices, and to try to identify what is effective in all human activities. We still need to consider how each materialism operates, what particular configuration it uses to account for these phenomena or how it bypasses the speeches of classical theory, forcing them to use their own objects.
Rather than supposing the existence of a single materialist theory, there is a need for investigation which takes in the diversity of these authors, situates them in their context and identifies the turning points which this general problem of the passions, which seems to have dominated for several centuries, encounters in each of them.