An initially appealing view about bodies is that they are volumes of solidity. However, this position was criticized by Hume on the grounds that it defines bodies as volumes of impenetrability by other bodies, which is circular.

We might think of bodies next as powers to produce certain effects. This is subject to a similar criticism, however, since this would imply that the effects produced are also powers. Powers end up being powers to produce powers which produce powers… and so on forever.

Howard Robinson argues that this should lead us to embrace idealism in his entry on idealism in the Oxford Handbook of Philosophy of Mind (p. 192).

If the physical realist is committed to the powers conception of matter, and if that conception is radically defective, then the physical realist is in trouble. Furthermore, his opponent will point out that, if the pure-powers conception is vicious, then the powers that are supposed to constitute matter must produce something which is not itself a power, but a monadic quality. And such qualities are to be found as sensible qualities in the sense fields of perceivers. So the physical world is a structured capacity to give rise to experience, and this is an idealist conception.

My inclination would be to say that just because we don’t know what bodies are does not mean that we should leap to idealism as an explanation. Maybe there is a better account of what bodies are that Robinson has not considered. Robinson might be sympathetic to this criticism, since he describes this reasoning as “slightly too swift” in a footnote to the quoted passage, and refers the reader to a book of his.