Why did Islamic philosophy refer to the Stoic Philosophers as the 'pneumatics'?

Question

In Glasners Averroes' Physics he writes:

The Arabs [Islamic Philosophers or Falsafa] were well familiar with Stoic logic, as well as with the basic ideas of Stoic philosophy. They learned about the Stoic school mainly from secondary sources and referred to them as ‘the pneumatics’ (ruhaiyyun).

This seems an odd choice of nomenclature. From my superficial knowledge of Stoic philosophy there doesn't appear to be a characteristic of stoic philosophy that this name is honouring.

Is there something I'm missing?

Answer 1

The term leads back to pneuma, a central concept in stoic metaphysics:

In Stoic philosophy, pneuma (πνεῦμα) is the concept of the "breath of life," a mixture of the elements air (in motion) and fire (as warmth). Originating among Greek medical writers who locate human vitality in the breath, pneuma for the Stoics is the active, generative principle that organizes both the individual and the cosmos. In its highest form, the pneuma constitutes the human soul (psychê), which is a fragment of the pneuma that is the soul of God (Zeus). As a force that structures matter, it exists even in inanimate objects.

More information to get started at the relevant WP page.