 (3) A stock objection to sense-data theories has been that they invite scepticism with regard to the external world. Broad regrets the sceptical consequences but—given the strength of the case for the sense-datum theory—does not consider them sufficient grounds for dismissal. Seeking to preserve as much as possible of the common sense notion of material objects he argues for the existence of such objects conceived of as having “primary qualities” such as shape, size, and position (apart from such properties as electric charge and mass). (1925, pp. 195–204.) Not surprisingly, he rejects the idea that material objects have “secondary properties” such as (phenomenal) redness or (phenomenal) hotness. Broad is perfectly clear that it does not follow from the fact that such properties are never sensuously manifested in our perceptual experiences that the material objects causing our experiences lack these properties: it does remain possible that there are red and green, hot and cold material objects even though they are not objects of acquaintance. He argues, however, that there is no reason to believe that material objects have these properties. (1925, pp. 205–6.)