The nature and definition of <answer>matter</answer> - like other key concepts in science and philosophy - have occasioned much debate. Is there a single kind of <answer>matter</answer> (hyle) which everything is made of, or multiple kinds? Is <answer>matter</answer> a continuous substance capable of expressing multiple forms (hylomorphism), or a number of discrete, unchanging constituents (atomism)? Does it have intrinsic properties (substance theory), or is it lacking them (prima materia)?
What is hyle?
matter