Certain conventional elementary ideas relating to the role of intermolecular attractions in liquids and gases are examined critically, and an effort is made to bring out a rationally defensible picture of the effects of these forces, without postulating the presence of any permanent, net force fields. A clear statement of the origin of surface tension is presented. The modification of pressure found in a real gas due to intermolecular attractions is shown not to be a boundary phenomenon. The need for a dynamic mechanism to account for this modification is pointed out.