Subjective Idealism (immaterialism or phenomenalism) describes a relationship between experience and the world in which objects are no more than collections or "bundles" of sense data in the perceiver. Proponents include Berkeley, Bishop of Cloyne, an Anglo-Irish philosopher who advanced a theory he called immaterialism, later referred to as "subjective idealism", contending that individuals can only know sensations and ideas of objects directly, not <answer>abstractions</answer> such as "matter", and that ideas also depend upon being perceived for their very existence - esse est percipi; "to be is to be perceived".
What did Berkeley consider things like matter to be?
abstractions