Posit

1 : to dispose or set firmly : fix
2 : to assume or affirm the existence of : postulate
3 : to propose as an explanation : suggest

Design exists because the world around us does not suit us and the goal of designers is to change the world through the creation of artefacts. They do this by positing functions to be achieved and producing descriptions of artefacts capable of generating those functions. In this sense, design is the opposite of the traditional scientific explanation.