The distinction between primary and secondary qualities, most famously
outlined by Galileo, and subsequently supported, inter alia, by
Descartes and by Locke, has widely been considered one of the crucial
factors in the development of modern idealism. In its contemporary form,
the distinction identifies some of the perceived properties as mental
phenomena due to their content and structural dependence on the mind.
However, this account of the primary/secondary distinction is largely
different from its original version developed by the above-mentioned
philosophers, within whose work the mental being of the perceived
qualities was demonstrated objectively, from the conceptually-derived
nature of matter, and not subjectively, by referring to the mind’s
participation in the cognitive process. It was only at the next stage of
the early modern subjectivisation of sense perception, best exemplified
by such philosophers as Arnold Geulincx and Richard Burthogge, that the
creative role played by the mind in sensation and, consequently, the
mind-dependency of the sensible qualities was recognised – a turn
influenced by the reinterpretation of Aristotelian philosophy offered by
Jacopo Zabarella and the Paduan school, as well as by
anti-Aristotelianism of the kind developed in Netherlands. Furthermore,
the two different approaches to the primary/ secondary distinction can
be linked with two main types of post-Cartesian idealism, i.e.
Berkeleian and Kantian – a claim for which illustrative evidence from
British philosophy, namely from Berkeley’s and Burthogge’s respective
theories, can be drawn.