 The property view is in part endorsed by the founding fathers of modern philosophy of perception, Galileo and Locke, who opened a tradition of lumping various sensory items in the class of secondary qualities. The typical seventeenth century list of secondary qualities includes colors, smells and sounds. No significant internal metaphysical differentiation is made within the class of sensory qualities, hence the charge of an oversimplification cannot be directly addressed to historical accounts. Other philosophers may have added shapes to the list (as Berkeley did), without addressing the issue of the homogeneity of the class: the issue was only whether shapes are secondary as sounds are, not whether they are on a par with sounds as to their structure.