Hegel used the concept of mediation in its most general meaning seeing in it the most characteristic property of mind. He said that the mind is as forceful as it is powerful. In general forcefulness consists in mediating activity that, while it lets objects act on each other according to their nature, and exhaust themselves in that activity, does not at the same time intervene in the process, but fulfills only its own proper role. Marx refers to this definition of the tools of work and indicates that Man ‘makes use of mechanical, chemical properties of things in order to change them into tools to act on other things according to his purpose (Vygotsky 1997b, pp. 61–62)
To 'act on' something can mean 'to alter, change or have an effect' on that thing. Fire acts on wood to make it into ashes; vodka acts on people to make them drunk; tools act on materials such as wood, metal, etc, to change their shape.
or act upon
VERB (intr, preposition)
- to regulate one's behaviour in accordance with ( advice, information, etc)
2. to have an effect on
The stirring music acted on the emotions of the audience